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1
de, la Mora Alejandra Nunez. "Developmental effects on reproductive hormone levels : a migrant study." Thesis, University College London (University of London), 2005. http://discovery.ucl.ac.uk/1446321/.
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Previous studies have established that average profiles of salivary progesterone and oestradiol, differ considerably among populations. Diet, age, and energetics appear responsible for acute inter-populational differences, but significant, unexplained differences in chronic levels of reproductive steroids remain. Based on developmental hypotheses advanced by reproductive ecologists, a migration study was initiated to assess whether environmental conditions experienced during development can influence patterns of adult ovarian hormones. Salivary steroid profiles of Bangladeshi women who migrated to the UK at different times (infancy, childhood, adulthood) were compared to those of women in Bangladesh, second-generation Bangladeshi migrants, and white women bom and resident in the UK. Data on socio- demographics, anthropometry, physical activity, diet and reproductive history were also collected. The following hypotheses and predictions were examined: A) Early life conditions influence adult set points of ovarian steroid hormones - women in Bangladesh and adult migrants will have lower ovarian steroids than child migrants, second generation and white women B) improved conditions during childhood can alter levels of ovarian steroids child migrants will have levels of ovarian steroids that are negatively correlated with age at migration and C) alterations in conditions after maturation do not modify set points established during early life - adult migrants will have steroid levels that are comparable to Bangladeshi sedentees. The predictions were upheld for progesterone but not for oestradiol. Results point to infancy and childhood as a sensitive period when changes in environmental conditions determine the tempo of growth and maturation, as well as later adult progesterone levels. In contrast, no evidence was found of a developmental effect on adult levels of oestradiol. The alterations in hormones levels among Bangladeshi migrants, together with a changing diet and reproductive behaviours, may put child migrants and second-generation women at increased risk for breast cancer in later life.
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Upton, Dannielle Heather. "Follicle stimulating hormone: ovarian reproductive function, health and aging." Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/15845.
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Follicle stimulating hormone (FSH) is vital for ovarian function; however elevated circulating levels are associated with reproductive ageing and ovarian tumorigenesis in women. Transgenic FSH (TgFSH) mice developed in our laboratory exhibit progressively rising FSH levels with ageing, causing ovarian dysfunction and premature infertility but no ovarian tumours. We hypothesized that high FSH may decrease oocyte developmental competence and quality with age and may also promote ovarian tumorigenesis when combined with ovarian mutations (such as in Pten, Brca1 and Trp53) in mice. Our first study examined the effects of elevated FSH on oocyte developmental capacity and quality (Chapter 3). Follicle stimulating hormone is vital for ovarian function and serum FSH increases with age as ovarian function declines towards menopause. We hypothesize that elevated FSH may rescue follicles from a diminishing pool normally excluded from selection, thereby reducing oocyte function. TgFSH mice expressing progressively rising FSH levels with age displayed increased litter size initially but after 6 months of age exhibited decreased litter size and premature infertility due to increased embryo-foetal resorption; however, the specific mechanism was undefined. We hypothesized that premature infertility observed was due to increased circulating FSH exceeding a threshold thereby impairing oocyte development and functionality. We examined oocyte in vitro maturation and aneuploidy and cumulus cells (from cumulus-oocyte complexes) for gene expression analysis in TgFSH and non-TgFSH control mice aged 6, 12, 18 and 24 months. Oocytes of TgFSH mice exhibited an increased percentage of cells remaining at the germinal vesicle (GV) stage, accompanied by a reduction in oocytes at the meiosis II (MII) stage of maturation vs age-matched littermate controls. The reduced oocyte progression to the MII stage is attributable to stalling of the oocytes in the GV stage. The proportion of aneuploid oocytes increased with age but did not differ between genotypes. We also wanted to examine cumulus cells matched to aneuploidy analysed oocytes for potential biomarkers of oocyte quality. A panel of 12 different candidate genes (Has2, Inhba, Egfr, Grem1, Tnfaip6, Ptgs2, Cyp19, Serpine2, Pgk1, Rgs2, Ctnnd2, Cxcr4) were examined by gene expression analysis utilising aneuploidy analysed oocyte matched cumulus cells revealing three potential markers (Egfr, Inhba, Rgs2) of oocyte quality.
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Jayasena, Channa N. L. "The effects of kisspeptin administration on reproductive hormone release in women." Thesis, Imperial College London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.535009.
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Wihlbäck, Anna-Carin. "Ovarian hormones and effects in the brain : studies of neurosteroid sensitivity, serotonin transporter and serotonin2A receptor binding in reproductive and postmenopausal women." Umeå : Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-365.
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Feehely, Kristie DeBlasio. "Relationship of Reproductive Hormone Levels and Menstrual Distress With Indices of Stress." NSUWorks, 2009. http://nsuworks.nova.edu/cps_stuetd/30.
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Previous research has found that hormone levels change throughout the phases of the menstrual cycle and can affect menstrual distress, however, with inconsistent results. Additionally, research has indicated that stress plays a role in menstrual distress symptoms. There has not been a comprehensive study to date which examines the relationship of reproductive hormone levels (e.g., progesterone, estradiol, LH and PRL) throughout all four phases of the menstrual cycle, while also studying menstrual distress symptoms and indices of stress. Participants include a community sample of women (N = 37) recruited at a university medical center in Mississippi who completed laboratory hormone assays, as well as the Menstrual Distress Questionnaire (Moos, 1968), the Weekly Stress Inventory (Brantley, Jones, Boudreaux, & Catz, 1997), and a global stress measure, throughout four phases of one menstrual cycle. Pearson correlations were conducted to test the potential relationships of hormone levels and indices of stress. The relationships between hormone levels and menstrual distress, as well as the relationships between menstrual distress and stress also were examined. Potential interactions were examined using multiple regressions. The role of menstrual distress in mediating the relationship between hormone levels and indices of stress also were considered and assessed using a series of multiple regression equations.
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Fronstin, Raime Blair. "Juvenile Hormone and Reproductive Tactics in Romalea Microptera, the Eastern Lubber Grasshopper." UNF Digital Commons, 2007. http://digitalcommons.unf.edu/etd/214.
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Isolated populations that inhabit various geographic and climatic ranges tend to diverge in their life history tactics. When development time is constrained by unfavorable seasons, often an organism must trade-off the investment of resource allocation between somatic and reproductive growth. The variation in reproductive tactics and juvenile hormone titers were studied among three populations of Romalea microptera from Athens, GA, Jacksonville, FL, and Miami, FL, all of which exist on a latitudinal cline. The Athens population was significantly younger at oviposition and gained significantly less body mass than both the Jacksonville and Miami populations, which did not differ from each other. Clutch mass did not differ across populations. With respect to both body size and oviposition age, Athens invested significantly more (measured by clutch size) to their first clutch than either Jacksonville or Miami, which did not differ from each other. Juvenile hormone and lipid profiles did not differ among populations. In response to the markedly reduced season length, results suggest that Athens grasshoppers respond with reproductive tactics that support terminal investment by investing more energy in less time to reproduction, at the expense of future reproduction.
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Hai, Lan. "EFFECT OF CONSTITUTIVELY ACTIVATED LUTEINIZING HORMONE RECEPTOR ON THE MOUSE REPRODUCTIVE SYSTEM." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1208.
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AN ABSTRACT OF THE DISSERTATION OF LAN HAI, for the Doctor of Philosophy degree in Molecular Cellular and Systemic Physiology, presented on 11th December, 2015 at Southern Illinois University Carbondale. TITLE: EFFECT OF CONSTITUTIVELY ACTIVATED LUTEINIZING HORMONE RECEPTOR ON THE MOUSE REPRODUCTIVE SYSTEM MAJOR PROFESSOR: Dr. Prema Narayan The luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is crucial for fertility, and genetic mutations in LHCGR cause adverse effects in reproductive development. Among the activating mutations identified in LHCGR, replacement of aspartic acid 578 by glycine (D578G) is the most common inherited mutation. Boys with this mutation undergo puberty by 2-4 years, caused by elevated testosterone in the context of prepubertal luteinizing hormone levels and present with Leydig cell hyperplasia. Clinically, these symptoms are associated with familial male-limited precocious puberty (FMPP). Our lab has published a mouse model for FMPP (KiLHRD582G) with D582G mutation equivalent to D578G in human LHCGR. We have previously demonstrated that KiLHRD582G male mice exhibited precocious puberty, Leydig cell hyperplasia and elevated testosterone and was a good model for FMPP. However, unlike women with the D578G mutation who show no abnormal phenotype, our studies revealed that female KiLHRD582G mice were infertile. KiLHRD582G female mice exhibit precocious puberty and irregular estrous cyclicity. A temporal study from 2-24 weeks of age indicated elevated steroid levels and upregulation of steroidogenic acute regulatory protein as well as several steroidogenic enzyme genes. Ovaries of KiLHRD582G mice exhibited significant pathology with the development of large hemorrhagic cysts as early as 3 weeks of age, extensive stromal cell hyperplasia with luteinization, numerous atretic follicles and granulosa cell tumors. Anovulation could not be rescued by exogenous gonadotropins. The body weights of the KiLHRD582G mice was higher that wild type counterparts, but there were no differences in the body fat composition. Hyperandrogenism and polycystic ovary phenotype was not accompanied by impaired glucose tolerance. Blocking the androgen action and estrogen synthesis indicated that reproductive phenotype was primarily due to excess estradiol. These studies demonstrate that activating LHCGR mutations do not produce the same phenotype in humans and mice and clearly illustrates species differences in the expression and regulation of LHCGR in the ovary. As we use male KiLHRD582G mice as breeders, we observed that the KiLHRD582G mice became progressive infertile, and only 8% of KiLHRD582G were fertile at 6 months of age despite normal sperm production. The infertile KiLHRD582G males were not able to form copulatory plugs in WT females, and mating studies suggested that the KiLHRD582G males were not capable of mating and/or ejaculating. Sexual behavioral testing revealed that the infertile KiLHRD582G males were capable of mounting the receptive WT females but were unable to achieve ejaculation indicating a problem with erectile and/or ejaculatory function. To address the reason for the ejaculatory dysfunction, we performed histopathological analysis of the accessory glands and penis. Hematoxylin and eosin staining showed that the normal columnar epithelium was replaced by pseudostratified columnar epithelium in the ampulla and several aggregates of chondrocyte metaplasia were apparent in the penile body of KiLHRD582G male mice. A temporal study indicated the histopathological changes in ampulla and penile body initiated at 7-8 and 12 weeks of age, respectively. Immunohistochemistry indicated that the chondrocytes stained positive for collagen type II, SOX9 and androgen receptor in the nucleus and for LHCGR in the cytoplasm. Penile fibrosis is a major cause of erectile dysfunction and is characterized by an increased collagen/smooth muscle ratio. However, our Image J analysis, hydroxyproline assay and western blot showed that KiLHRD582G penile body exhibited reduced levels of smooth muscle actin but similar total collagen content compared to WT mice. Thus, penile fibrosis was not responsible for the progressive infertility of adult KiLHRD582G mice. We also observed Leydig cell adenoma and disruption of spermatogenesis at 1 year of age. Our results suggest FMPP patients may be susceptible to infertility and testicular tumors later in their life and a follow-up study of FMPP patients is recommended.
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Jones, Geraint Vaughan. "Intrauterine effects of male mouse fetuses on the adult reproductive physiology of their female siblings." Thesis, Keele University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358556.
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Hogg, Carolyn J. "Development of a non-invasive technique to determine reproductive hormones in cetaceans." Faculty of Veterinary Science, 2006. http://hdl.handle.net/2123/1865.
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Doctor of Philosophy (PhD)Reproductive physiology plays a vital role in population growth and vitality. Baseline data on reproductive physiology and a comprehensive knowledge of breeding biology are essential to conservation management. Great whales have been hunted from the 16th century to the present day. Although many populations are increasing there are populations with low or declining reproductive rates. In 2001 it was recommended to the International Whaling Commission that new techniques be developed to assess the internal physiology of great whales. This study, based on this recommendation, aims to develop analytical methods to assess reproductive hormones in cetacean blow samples and determine the feasibility of its use with free-swimming great whales. A method for the assessment of steroid hormone concentrations using liquid chromatography-mass spectrometry (LC-MS) was developed and validated. These methods were then used to determine testosterone and progesterone concentrations in saliva and blow of bottlenose dolphins. The stability of testosterone and progesterone was found to be a major issue. Without inhibitors, hormone concentrations increased by up to 65% over three hours at 21oC. Storing samples at low temperatures (-20oC or -80oC) slowed but did not cease the rate of change. The addition of inhibitors, manganese chloride and amoxycillin potassium/clavulanate, improved the stability of testosterone and progesterone. It is proposed that when using dolphin saliva and blow samples to measure reproductive hormones the samples are extracted as soon as possible after collection to prevent degradation. This study highlighted the need to address steroid hormone stability prior to any longterm biological program, to ensure that changes seen in hormone concentration are due to biological activity rather than storage. A technique to collect blow samples from free-swimming great whales was developed. This technique, in conjunction with the specially developed LC-MS methods allowed for the determination of testosterone and progesterone concentrations in humpback whale blow. The techniques developed in this study to determine reproductive hormones in cetacean saliva and blow have applications for both captive and wild population studies. In captive institutions, saliva and/or blow can be used to monitor reproductive cycling in both females and males. As it is noninvasive it can be used on a daily basis with minimal stress to the animals. The use of blow sampling has the capacity to improve our understanding of reproductive cycling in great whales as it can be used to sample animals in both the breeding and feeding areas. This technique may allow us to now examine whether reproductive dysfunction is playing a role in the slow recovery of critically endangered species such as the North Atlantic right whale.
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Hogg, Carolyn J. "Development of a non-invasive technique to determine reproductive hormones in cetaceans." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/1865.
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Reproductive physiology plays a vital role in population growth and vitality. Baseline data on reproductive physiology and a comprehensive knowledge of breeding biology are essential to conservation management. Great whales have been hunted from the 16th century to the present day. Although many populations are increasing there are populations with low or declining reproductive rates. In 2001 it was recommended to the International Whaling Commission that new techniques be developed to assess the internal physiology of great whales. This study, based on this recommendation, aims to develop analytical methods to assess reproductive hormones in cetacean blow samples and determine the feasibility of its use with free-swimming great whales. A method for the assessment of steroid hormone concentrations using liquid chromatography-mass spectrometry (LC-MS) was developed and validated. These methods were then used to determine testosterone and progesterone concentrations in saliva and blow of bottlenose dolphins. The stability of testosterone and progesterone was found to be a major issue. Without inhibitors, hormone concentrations increased by up to 65% over three hours at 21oC. Storing samples at low temperatures (-20oC or -80oC) slowed but did not cease the rate of change. The addition of inhibitors, manganese chloride and amoxycillin potassium/clavulanate, improved the stability of testosterone and progesterone. It is proposed that when using dolphin saliva and blow samples to measure reproductive hormones the samples are extracted as soon as possible after collection to prevent degradation. This study highlighted the need to address steroid hormone stability prior to any longterm biological program, to ensure that changes seen in hormone concentration are due to biological activity rather than storage. A technique to collect blow samples from free-swimming great whales was developed. This technique, in conjunction with the specially developed LC-MS methods allowed for the determination of testosterone and progesterone concentrations in humpback whale blow. The techniques developed in this study to determine reproductive hormones in cetacean saliva and blow have applications for both captive and wild population studies. In captive institutions, saliva and/or blow can be used to monitor reproductive cycling in both females and males. As it is noninvasive it can be used on a daily basis with minimal stress to the animals. The use of blow sampling has the capacity to improve our understanding of reproductive cycling in great whales as it can be used to sample animals in both the breeding and feeding areas. This technique may allow us to now examine whether reproductive dysfunction is playing a role in the slow recovery of critically endangered species such as the North Atlantic right whale.
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Gladstones, Gwyneth H. "Glucocorticoid metabolism and action in the rat epididymis." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2009. https://ro.ecu.edu.au/theses/1825.
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Glucocorticoid hormones are known to be essential for numerous physiological processes and are released in response to stress, via negative feedback mechanisms on the HPA axis. In humans the main glucocorticoid is cortisol and in rats, corticosterone. Glucocorticoid levels in target tissues are regulated by the glucocorticoid receptor (GR), cortisol-binding globulin (CBG) and the two 11β -hydroxysteroid dehydrogenase enzymes (11 β-HSD-1 and 2) that interconvert active and inactive glucocorticoids. The 11 β-HSD-1 enzyme acts both as a reductase ( converting inactive cortisone to cortisol in humans and 11- dehydrocortisone to corticosterone in rats) and a dehydrogenase (inactivating glucocorticoids), although largely functions as a reductase in vivo. In contrast, 11 β-HSD-2 acts exclusively to inactivate excess cortisol or corticosterone allowing aldosterone to bind to the mineralocorticoid receptor (MR) in specific tissues.
Stress-related increases in active glucocorticoids may negatively affect male reproduction by decreasing testosterone levels in Leydig cells. Glucocorticoids have been suggested to have both pro-oxidative and anti-oxidative properties and oxidative stress is reported to contribute to impaired sperm maturation and infertility. Sperm mature and reach full fertilising potential as they pass through the epididymis and cells comprising the epididymal epithelium have essential roles in maintaining an optimal luminal fluid environment.
The 11 β-HSD-1 and 2 enzymes have been localised in the adult rat epididymis, suggesting that corticosterone may influence sperm maturation, however a precise role for glucocorticoids in the epididymis has not previously been investigated. Therefore, the aims of this thesis were to examine the postnatal developmental localisation of 11β-HSD-1 and 2, GR, MR and Na+K+-ATPase in the rat epididymis and investigate both a possible role for glucocorticoids in mediating oxidative stress during sperm maturation and the regulation of 11 β-HSD- 1 and 2 in the adult rat epididymis.
The results from the first study demonstrated 11 β-HSD-1, the GR and MR localisation in the epididymal epithelium from postnatal day 1 (pnd 1) and 11β HSD-2 and Na+K+-ATPase reactivity from pnd 15. At pnd 28 there was maximal immunoreactivity for both the GR and MR and 11β ~-HSD-1 and 2, coinciding with the differentiation of epididymal principal and basal cells and the preparation for the arrival of sperm in the lumen at puberty (pnd 40). Relative mRNA levels of 11β ~-HSD-1 and 2 were compared at pnd 28 and 75. Levels of 11β ~-HSD-1 mRNA were higher at pnd 75 than at pnd 28 (pp+K+-ATPase ), leading to epithelial cellular deterioration. In the epididymis this could disrupt ion and fluid transport and damage tight junctions forming the blood-epididymis barrier, having deleterious effects on sperm maturation. All treatments increased the absolute intensity (Al) of 4-HNE immunoreactivity (p+K+-ATPase Al (p
Collectively, the results suggest that an intricately regulated and finely balanced level of glucocorticoids are maintained, both during postnatal maturation of the rat epididymis and in the adult epididymis, to regulate epididymal cell differentiation and maturation, preserve appropriate ion and fluid transport processes and mediate levels of reactive oxygen species (ROS) required for normal sperm maturation. Furthermore, at excess levels, glucocorticoids may be detrimental to normal epididymal maturation and function, possibly causing epithelial oxidative stress and impaired sperm maturation.
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Barron, Anna May. "The role of the female reproductive hormones in Alzheimer's disease." University of Western Australia. School of Psychiatry and Clinical Neurosciences, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0205.
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[Truncated abstract] Alzheimers disease (AD) is a progressive neurodegenerative disease which manifests clinically as personality changes and global cognitive decline resulting in a loss of function, ultimately leading to death. Whilst causal genetic mutations have been identified, accounting for a small proportion of familial cases, the vast majority of all AD cases are late onset and idiopathic. However, a number of risk factors have been identified, including age associated changes in the reproductive hormones estrogen and the gonadotropins. Previous in vitro and in vivo studies have implicated both estrogen and the gonadotropins in the regulation of the neurotoxic beta amyloid (Aß) peptide, accumulation of which is thought to be a key pathogenic event in the development of AD, but the role of these hormones in the etiology and pathogenesis of AD remains contentious. The aim of this thesis was to further understanding of the role of female reproductive hormones in modulating susceptibility to AD. The role of menopausal hormone dysregulation in behavior, cognitive decline and Aß-related neuropathology was examined in vivo in 4 studies using animal models of AD and menopause. The first two studies used a mouse model of AD expressing a human PS1 mutation (PS1KI) to examine the effects of ovariectomy as a model of menopause on cognition and neuropathology. Ovariectomy was found to selectively impair learning on a spatial working memory task without affecting working memory recall or reference memory performance. However, this cognitive impairment was not associated with any changes in Aß accumulation or oxidative stress. ... However, these findings cannot explain the lack of effect of estrogen supplementation on Aß levels. It is possible that supra-physiological doses of estrogen are necessary to yield anti-amyloidogenic and anti-oxidative benefits in ovariectomized sheep. It is becoming clear that the relationship between hormone changes at menopause and risk of AD may be more complicated than previously conceived. This study has begun to tease apart the relative contributions of estrogen and the gonadotropin hormones in the modulation of Aß, accumulation of which may confer susceptibility to AD. The findings presented indicate that the gonadotropins may play an important role in the regulation of AD-related behavior and cognition. The observed functional effects of the gonadotropins may also have implications for our understanding of behavioral and cognitive changes occurring during reproductive events. Based on the evidence presented here, combined with previous literature, it is clear that both estrogen and the gonadotropins are involved in the modulation of Aß accumulation, however, elucidation of the circumstances necessary to elicit these effects and their clinical relevance to humans will require further investigation. These findings contribute to a more sophisticated understanding of the post-menopausal hormonal milieu, recognizing the role of the gonadotropin hormones and that gonadal estrogen depletion does not necessarily result in brain estrogen depletion.
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Nisbeth, Sofie. "Oncologists´ perspectives and practice on exogenous reproductive hormone use in breast cancer patients." Thesis, Örebro universitet, Institutionen för medicinska vetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-86203.
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Purpose: the study aimed to investigate oncologists´ perspectives and practices on their prescription of oral hormonal contraceptives (OHC), menopausal hormone therapy (MHT) and local estrogen therapy in patients with prior breast cancer diagnosis or BRCA-mutation carriers. Method: The study was a web-based survey, based on fictional patient cases that was sent out to 134 breast oncologists in Sweden. Thirty-six oncologists responded and included in the analysis. Results: Most oncologists would not recommend MHT after breast cancer diagnosis except from the case of estrogen-receptor negative disease where 38.9% would recommend. Similarly, non-hormonal contraceptives were recommended from most oncologists in different clinical scenarios. Regarding MHT in BRCA-mutations carriers, 11.1% would recommend MHT in patients without mastectomy whereas 50% would recommend MHT in patients who have undergone prophylactic mastectomy. Non-hormonal treatment followed by low-dose estriol were the most common treatment strategies for dry vagina after breast cancer diagnosis among oncologists whereas estriol-containing treatment was also a relatively common approach in patients treated with tamoxifen. Conclusion: We found unanimous practices in some clinical scenarios where there is some evidence, and more variable practice where the evidence is weak or completely absent. The presence of guidelines for some clinical scenarios seems to increase the common view among oncologists.
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Costas, Caudet Laura. "Reproductive factors, hormone use, and endocrine disruptors in the etiology of lymphoid neoplasms = Factors reproductius, ús d’hormones i disruptors endocrins en l’etiologia de les neoplàsies limfoides." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/565936.
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Lymphoid neoplasms are a heterogeneous group of cancers characterized by the neoplastic or clonal proliferation of lymphoid cells in different stages of differentiation. The incidence rate of these neoplasms has seen a rise in some western countries since the 1970s and it seems to have reached a plateau during the last decade. Incidence rates are higher in men than in women for most lymphoma subtypes; however, the causes explaining these differences by sex are unknown. We hypothetised that hormonal factors could have a role in lymphoma etiology.
The general aim of this thesis was to assess the risk of lymphoid neoplasms in relation to reproductive factors and occupational exposure to endocrine disruptors. We used different studies and populations to evaluate our hypothesis: the EpiLymph study, the InterLymph consortium, the International Multiple Myeloma Consortium, and a systematic review. As well, we developed a new tool to estimate occupational exposures to a specific type of endocrine disruptors.
We observed contradictory findings across studies and lymphoma subtypes concerning the association between lymphoma and parity, as well as hormonal contraceptives. We observed inverse associations between postmenopausal hormone therapy and lymphoma, although we noticed in our systematic review that cohort studies usually found null associations. We observed associations with lymphoma and prolonged (≥30 years) occupational exposure to endocrine disrupting chemicals, in particular for multiple myeloma and chronic lymphocytic leukemia. Associations were observed between lymphoma and prolonged occupational exposures to organic solvents, pesticides, brominated flame retardants, alkylphenolic compounds, and metals. To further explore the associations with alkylphenolic compounds, we developed a job-exposure matrix on these compounds considering relevant changes in use over time.
In conclusion, our results indicate that reproductive factors and exogenous hormone use are unlikely to play a role in lymphomagenesis. The associations between occupational exposure to endocrine disrupting chemicals and lymphoma need to be further explored in studies using a more detailed exposure assessment.
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Cimino, Irène. "Study of new molecular factors regulating GnRH migration, axonal targeting and neurosecretion : insights into the acquisition of reproductive competence." Thesis, Lille 2, 2014. http://www.theses.fr/2014LIL2S044/document.
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Chez les mammifères, la reproduction est regulée par des neurones spécifiques qui sécrètent le neuropeptide GnRH (Gonadotropin Releasing Hormone). Ces cellules naissent au stade prénatal dans la placode nasale et migrent dans l'hypothalamus, le long des nerfs olfactifs voméro-nasaux, pour devenir des membres à part entière de l'axe hypothalamo-hypophyso-gonadique. Un certain nombre de pathologies de la reproduction humaine sont associées à la perturbation soit de la migration neuronale des cellules à GnRH ou soit de la sécrétion de la GnRH.L'objectif général de ma thèse était d'identifier de nouveaux facteurs moléculaires régulant la migration des cellules à GnRH, leur ciblage axonale à l'éminence médiane, mais aussi leur neurosécrétion au cours de la vie reproductive.Les événements complexes du développement correcte du système à GnRH sont strictement régulés par l'expression spatio-temporelles des molecules de guidage et des molécules de la matrice extracellulaire, dont les fonctions, sont en partie médiées par leur liaison avec la β1-intégrine (Itgb1). La première partie de mon travail a été d’étudier le rôle biologique de ces protéines de surface dans la reproduction. La technologie Cre/loxP a été utilisée pour générer des souris conditionnelles GnRH spécifiques KO pour la β1-intégrine (GnRH-Itgb1-/-). La perte d’activité de la β1-intégrine altére la migration des neurones à GnRH, leur extension axonale à l’eminence mediane et la fertilité de ces souris. Ces résultats mettent en évidence que la β1-intégrine joue un rôle important dans le développement normal du système GnRH et dans l'acquisition de compétences reproductives normales chez les rongeurs.Dans la deuxième partie de ma thèse de doctorat, j'ai identifié de nouveaux facteurs moléculaires qui pourraient être responsables de l'apparition du syndrôme des ovaires polykystiques (SOPK). Cette maladie est présente chez près de 10 % des femmes. Il s’agit d’une hyperandrogénie associée à une oligo-anovulation chronique, une morphologie ovarienne polykystique et d'autres situations cliniques de transition d'un état endocrinien à un autre. Chez les patientes atteintes du SOPK, le niveau d'hormone antimüllérienne (AMH) est élevé et indique clairement que l'AMH pourrait est un marqueur possible dans le diagnostic et le traitement du SOPK. Une autre manifestation du syndrome est une élévation des sécrétions du GnRH provoquant une augmentation des taux de LH et un rapport LH/FSH élevés, qui stimulent la production d'androgènes ovariens. Toutefois, jusqu'à présent cette maladie a été considérée principalement comme une pathologie gonadique et des régulations possibles plus élevées au niveau du système nerveux central ou des interactions avec ce dernier n'ont pas été étudiées. En particulier, des informations concernant les effets extra-ovariens possibles de l'AMH sur l'axe hypothalamo-hypophyso-gonadique manquent actuellement. Mon projet de recherche a été d’étudier le rôle encore méconnu de l'AMH dans la régulation de la physiologie du système à GnRH. Mes études ont permis d’identifier un nouveau rôle extra-ovarien pour l'AMH, et notamment comme un puissant activateur de la neurosécrétion de la GnRHDuring aging, oxidative stress occurs characterized by an imbalance between the production reactive oxygen species and antioxidant capacity. It’s well recognized that acute exercise induces oxidative stress which response may be affected by aging. Only few studies have focused on the response of oxidative stress parameters to an acute exercise in relation with aging and they were not made in humans. The first aim of this work was to investigate the response of oxidative stress parameters to acute exercise in young and older subjects. Our results showed that aging has no effects on oxidative stress parameters at rest. However, in response to an acute physical exercise, our results showed that aging is characterized by an antioxidant defenses deficiency and an increase in free radical damage markers. On the other hand, regular physical activity is considered as an effective way to reduce free radical attacks and enhance the antioxidant defense. These adaptations to regular physical activity are often related to the level of physical activity and this has been shown in young subjects. The second aim of this work was to study oxidative stress parameters in elderly subjects with different physical activity levels. Our results showed a positive correlation between physical activity level and antioxidant potential. However, physical activity at high level increases free radical damage in older adults. In view of changes in oxidative stress parameters with aging, adaptations of those to regular physical activity could also be affected by aging phenomena. The aim of the third study of this work was to investigate the effects of aging and physical activity level on oxidative stress parameters responses to an acute exercise. To do so, we compared these parameters in two young subjects groups (active and sedentary) and two older adults groups (active and sedentary) before and after an acute exercise. Our results showed that, benefits of regular physical activity on the oxidative parameters stress were more pronounced in younger age groups compared to older groups. On the other hand, the effects of aging on oxidative stress parameters in the active groups were lower than those noted in the sedentary groups
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Johnson, Justin M. "Characterization of the Immune Response to Anti-Müllerian Hormone." Cleveland State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=csu1606840042907281.
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Rekik, M. "Effect of rams and pretreatment with progesterone or melatonin upon gonadotrophin secretion, follicular development and reproductive performance of anoestrous adult ewes." Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383421.
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Misu, Ryosuke. "Development of Neuropeptide Receptor Ligands for the Control of Reproductive Systems." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199501.
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Pickin, Charles Benjamin. "Reproductive performance of Holstein cows treated with prostaglandin F2a, gonadotropin releasing hormone, and recombinant bovine Somatotropin." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/10171.
Full textAbstract:
The objective of this study was to examine the effects of presynchronization and recombinant bovine somatotropin (rbST) on conception rates following a timed insemination (TAI) protocol in lactating dairy cows. A further objective included the evaluation of the efficacy of the Early Conception Factor (ECF) test kit. Recombinant bST may offer some benefit when used in conjunction with estrus synchronization and TAI. Presynchronization treatment consisted of two injections of PGF2α given 14 d apart, with the second dose administered 14 d prior to the initiation of a TAI protocol. A total of 216 lactating Holstein cows were presynchronized with PGF2α and then received GnRH (100μg) at 67 ± 7 d post partum (PP), administration of PGF2α (25 mg) 7 d later, another GnRH (100μg) administration 2 d after PGF2α, and were inseminated 8-18h later (OvSynch). First service conception rate (CR) was determined by rectal palpation at 42 ± 7 d after artificial insemination (AI). Treated cows (n=113) received rbST 67 ± 7 d PP whereas control cows (n = 113) were presynchronized without rbST. The cycling status of all cows was determined by paired milk P4 levels at 53 and 67 ± 7 d PP. No differences (P > 0.10) in conception rate were observed between control and rbST treated cows (44.7 and 40.7% respectively), nor was there any interaction of cyclicity and rbST. Milk samples were collected 7 d following AI for use in ECF test kit evaluation. Samples were stored at -20ºC (n=216) and at 5ºC (n=113) until assayed. Test results for frozen and refrigerated samples were compared to conception rates determined by rectal palpation at 42 ± 7 d after AI. The rate of false positive and negative results for frozen milk samples were 36.1 and 14.8% respectively, and 40.7 and 7.1% for refrigerated milk samples. Treatment with rbST at the time of the first GnRH injection of an OvSynch protocol did not significantly alter first service conception rates. Additionally, an acceptable 92.9% accuracy of the ECF test for the detection of open cows 7 d after AI using milk samples stored at 5ºC was obtained.Master of Science
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Waye, Andrew. "An Investigation of Pulp Mill Effluents and Their Wood Feedstocks as Potential Neuroendocrine Disruptors of the Fish Reproductive Axis." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32145.
Full textAbstract:
Common observations of reduced gonad size and spawning inhibition in wild and laboratory raised fish exposed to pulp mill effluents indicate that reproductive neuroendocrine signalling pathways may be upset. This thesis supported the neuroendocrine disruption of reproduction hypothesis by identifying potential disruptors and targets where these impacts may occur. A mechanistic study of the in vivo fathead minnow (FHM) spawning assay used by industry to assess effluent quality showed that ovulation, but not milt production, was impaired. This finding supported the hypothesis that the neuroendocrine cascade that triggers ovulation may be disrupted. I hypothesized that neuroactive constituents previously described in effluents were originating in wood feedstocks and neuroactive extracts of hardwood and conifer feedstocks were identified. Phytochemicals associated with effluents were neuroactive. Structurally similar phenolic phytochemicals showed monoamine oxidase (MAO) inhibition, and resin acid diterpenes displayed glutamic acid decarboxylase (GAD) inhibition. Inhibitors of these enzymes may have impacts on the control of reproduction since MAO metabolizes dopamine, an inhibitor of the neuroendocrine reproductive axis, while GAD synthesizes -aminobutyric acid (GABA), a stimulator of this axis. Bioassay-guided fractionations of effluents and wood feedstocks identified that medium polar extracts of primary- and secondary-treated effluents and balsam fir feedstock contained high GAD inhibitory activity. This activity was associated with chemically complex fractions rather than single active principles. Advanced metabolomic comparison of medium polar extracts of feedstock and treated effluent identified 15 common plant metabolites, demonstrating that phytochemicals entering the mill in wood are surviving pulp production and effluent treatment processes and may be responsible for observed GAD inhibition. Discriminant metabolomics analysis identified 4-acetylpyridine, a novel compound to be described in effluents, as well as two other tentatively identified compounds, as chemical markers of GAD inhibitory effluent fractions. Five tentatively identified chemical markers and (+)-lariciresinol were found in inhibitory balsam fir feedstock fractions. Neuroendocrine pathways that control reproduction in fish, such as dopamine and GABA pathways, are also important drug targets for the treatment of neurological disorders in mammals; therefore these results also have implications for the development of natural health products from phytochemicals and tree extracts common to Canadian forests. By using an interdisciplinary approach (phytochemistry, neuroendocrinology, ecotoxicology), I was able to explore the various implications of my research on the fields of natural health products chemistry and aquatic toxicology.
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Laviolette, Laura. "The Effects of the Female Reproductive Hormones on Ovarian Cancer Initiation and Progression in a Transgenic Mouse Model of the Disease." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19939.
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Ovarian cancer is thought to be derived from the ovarian surface epithelium (OSE), but it is often diagnosed during the late stages and therefore the events that contribute to the initiation and progression of ovarian cancer are poorly defined. Epidemiological studies have indicated an association between the female reproductive hormones and ovarian cancer etiology, but the direct effects of 17β-estradiol (E2), progesterone (P4), luteinizing hormone (LH) and follicle stimulating hormone (FSH) on disease pathophysiology are not well understood.
A novel transgenic mouse model of ovarian cancer was generated that utilized the Cre/loxP system to inducibly express the oncogene SV40 large and small T-Antigen in the OSE. The tgCAG-LS-TAg mice developed poorly differentiated ovarian tumours with metastasis and ascites throughout the peritoneal space. Although P4 had no effect; E2 significantly accelerated disease progression in tgCAG-LS-TAg mice. The early onset of ovarian cancer was likely mediated by E2’s ability to increase the areas of putative preneoplastic lesions in the OSE.
E2 also significantly decreased survival time in ovarian cancer cell xenografts. Microarray analysis of the tumours revealed that E2 mainly affects genes involved in angiogenesis and cellular differentiation, proliferation, and migration. These results suggest that E2 acts on the tumour microenvironment in addition to its direct effects on OSE and ovarian cancer cells.
In order to examine the role of the gonadotropins in ovarian cancer progression, the tgCAG-LS-TAg mice were treated with 4-vinylcyclohexene-diepoxide (VCD) to induce menopause. Menopause slowed the progression of ovarian cancer due to a change in the histological subtype from poorly differentiated tumours to Sertoli tumours.
Using a transgenic mouse model, it was shown that E2 accelerated ovarian cancer progression, while P4 had little effect on the disease. Menopause (elevated levels of LH and FSH) altered the histological subtype of the ovarian tumours in the tgCAG-LS-TAg mouse model. These results emphasize the importance of generating animal models to accurately recapitulate human disease and utilizing these models to develop novel prevention and treatment strategies for women with ovarian cancer.
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Wong, Chi-wai, and 汪志偉. "Intermedin and its receptor components in the reproductive systems of the rat and the effect of intermedin on uterine contraction." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48521899.
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Intermedin (IMD) is a peptide hormone discovered in 2004 belonging to the calcitonin/calcitonin gene-related peptide superfamily. It signals through a Gprotein coupled receptor by the coupling of a calcitonin receptor-like receptor (CRLR) and one of the receptor activity-modifying proteins (RAMPs) 1-3. Due to its similarity to adrenomedullin in structure and functions, IMD is also known as adrenomedullin 2 (ADM2).
Among members of the superfamily, IMD shares the highest degree of homology with ADM, which is a multifunctional vasodilator ubiquitously expressed in various tissues and organs and has been studied by our group for its reproductive functions. It is hypothesized that IMD may be present in the reproductive systems of the rat and exert some effects on reproductive functions.
The objectives of this study were to investigate the expression of IMD and its receptor components in the male and female reproductive systems of the rat, the changes in expression across the oestrous cycle, and its effect on uterine contraction. The gene expression levels of Imd and its receptor components and peptide levels of IMD were measured by RT-PCR and enzyme immunoassay respectively. The effect of IMD on the uterine contraction was studied by the organ bath technique.
Imd mRNA and IMD levels were detected in the testis, epididymis, ventral prostate, coagulating gland, and seminal vesicle of the male rat and the ovary, oviduct, and uterus of the female rat, suggesting possible roles for IMD in both the male and female reproductive systems. In the male, the Imd mRNA levels were the highest in the seminal vesicle but lowest in the testis and the epididymis and IMD peptide levels were the highest in the coagulating gland but lowest in the epididymis. In the female, the Imd mRNA and IMD peptide levels were the highest in the oviduct and the uterus respectively while both the Imd and IMD levels were the lowest in the ovary.
Imd mRNA and IMD levels displayed cyclic changes in various female reproductive tissues across the oestrous cycle. In the ovary, positive immunostaining was detected in the follicles and corpora lutea with more staining in the latter. The Imd mRNA level was significantly higher at prooestrus than dioestrus while the IMD peptide level was significantly higher at metoestrus than dioestrus. In the oviduct, the Imd mRNA level was the lowest at dioestrus but the IMD peptide level was the highest at dioestrus. Positive immunostaining was observed in the ciliated epithelial cells. Uterine Imd mRNA level was the highest at prooestrus while the IMD level was the highest at dioestrus. IMD was found in the luminal and glandular epithelia.
IMD significantly reduced the uterine contraction amplitude and frequency but not the basal tone. CGRP receptor antagonist hCGRP8-37 and ADM receptor antagonist hADM22-52 partially abolished the inhibitory effect of IMD on uterine contraction while the IMD specific receptor antagonist hIMD17-47 completely blocked the actions. Enzyme inhibitors of NO (L-NAME) and PI3K (Wortmannin) pathways diminished the IMD-mediated effects on uterine contraction while cAMP/PKA blocker KT5720 had no effect.published_or_final_version
Physiology
Master
Master of Philosophy
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Johnsen, Hanna. "The Importance of the TSHR-gene in Domestic Chicken." Thesis, Linköpings universitet, Biologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-103687.
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Thyroid hormones are known to be important in several processes in chicken, such as growth, metabolism and reproductive system. In previous studies the thyroid stimulating hormone receptor (TSHR)-gene has been identified as a target for a selective sweep in commercial breeds of chicken such as broiler and White Leghorn. The evolution of domesticated species can be split into three periods. The first is the natural selection in their natural habitat, the second the beginning of the domestication process, when humans started to tame and breed the wild animals and the third is when animals were bred for commercial interests such as egg laying properties and meat production in chicken. Landraces, which are domesticated but not commercially bred races, are a great resource for identifying during which period a specific gene, which differs between wild type and commercial bred breeds, were selected. In this study Swedish landrace chickens were used in order to analyze the importance of a mutation in the TSHR-gene in the domestication process. The results of this study gave that all, except two individuals from the Bohuslän-Dals svarthöna were homozygous for the mutation known from commercial breeds. The two individuals from Bohuslän-Dals svarthöna were both heterozygous for the mutation. These results suggest that the TSHR mutation is important for the domestication process and were already more or less fixed at the commencement of commercial breeding. The mutation is thought to be dominant and to have an inhibitory impact on the TSHR activity. This might result in hypothyroidism which would make alterations in the reproductive system. This is plausible because the constant availability of food in captivity makes the seasonal reproductive system no longer critical for survival of progeny.
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Fernandes, Maria Sofia Pinto. "Expression and Role of Putative Membrane Progestin Receptors in Non-Genomic Hormone Actions in the Female Reproductive Tract." Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486555.
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The steroid hormone oroaesterone exerts pleiotrophic functions in many cell types and has a key role In many aspects of female reproduction. It is well established that progesterone controls transcriptional activation through binding to nuclear progesterone receptors. However. progesterone also initiates rapid non-genomic signalling events. but the underlying mechanisms are poorly understood. Recently. a group of potential membrane progesterone receptors (mPRc.c B. y) was isolated from the spotted seatrout and subseguently identified in many other species. The mPRs belong to the larger. highly conserved family of progestin and adiponectin receptors (PAQR) and have structural similarity to seven transmembranespanning G protein-coupled receptors. To further define the role of these mPRs in human reproductive tissues expression profiling was performed. A comparison of the expression of mPR transcriots with that of two related PAQR family members. PAQRIII and PAQRIX. in cycling endometrium and pregnancy tissues revealed markedly divergent expression levels and profiles. However. functional analyses demonstrated that neither human or fish mPRs mediate cAMP production. Mitogen-activated protein kinase activation or�· calcium mobilization in response to progesterone. Furthermore. human mPRa localizes to the endoplasmic reticulum and not the plasma membrane. Other putative progesterone binding moieties. inclUding progesterone receptor membrane component 1 and 2 (PGRMC-1/-2). were also investigated. Like PAQR family members, PGRMC-1 and -2 are expressed in a reoulated manner in pregnant and non-pregnant uterine tissues but evidence of their roles in prooesterone responses remains elusive. Thus. these results do not support a role for the mPRs in non-genomic proaesterone signal transduction in human uterine tissues.
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Lind, Craig Michael. "The Relationship Between Plasma Steroid Hormone Concentrations and the Reproductive Cycle of the Northern Pacific Rattlesnake, Crotalus oreganus." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/110.
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To gain a better understanding of the role of steroid hormones in vertebrate reproduction, we quantified steroid hormone concentrations in a free ranging population of the Northern Pacific rattlesnake, Crotalus oreganus. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (Mar-Oct). We measured testosterone (T), 5α-dihydrotestosterone (DHT), and corticosterone (B) concentrations in male and female snakes. 17β-estradiol (E2) and progesterone (P) were measured in females only. We also observed breeding behaviors (e.g. consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections. Our results indicate that C. oreganus in central California utilizes a bimodal pattern of breeding, with mating and agonistic behavior occurring in the spring and the late summer/fall. Each breeding season corresponds with elevated or highly variable androgen (T and DHT) levels. Several female snakes had high E2 concentrations in the spring and fall, coincident with vitellogenesis and mating. Females with high E2 concentrations also had high T and DHT concentrations. Corticosterone concentrations in males are not related to either time of year or concentrations of any other hormones quantified. This suggests that the breeding season in this population may not demand a significant increase in energy mobilization by glucocorticoids. Measurements of testis volume show that testes are regressed in the spring when the majority of breeding was observed in this population and reach peak volume in August and September during spermatogenesis. Multiple regression analyses revealed that in female snakes, P is positively correlated with T and DHT, and E2 is correlated with T. Since these results are strictly descriptive, experimental studies are needed to identify the functional significance of these results.
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Snell-Bergeon, Janet K. "Reproductive history and sex hormones and their association with subclinical atherosclerosis in women with and without type 1 diabetes /." Connect to full text via ProQuest. Limited to UCD Anschutz Medical Campus, 2007.
Find full textAbstract:
Thesis (Ph.D. in Epidemiology) -- University of Colorado Denver, 2007.Typescript. Includes bibliographical references (leaves 100-117). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;
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Bahougne, Thibault. "Perturbation de la rythmicité circadienne : impact sur la fonction reproductive de souris femelles." Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAJ001.
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Chez les mammifères femelles, la fonction reproductive dépend à la fois d’une horloge biologique synchronisée par le cycle lumière/obscurité et par un équilibre entre le rétrocontrôle négatif et positif des œstrogènes, dont les concentrations varient en fonction de la maturation folliculaire. Chez les femmes, un nombre croissant d’études signalent un impact négatif des environnements chronodisruptifs, comme le travail posté / de nuit, sur la fertilité. Les objectifs de mon travail étaient d’étudier les effets d’un décalage de phase unique ou chronique sur les cycles reproducteurs de souris (C57BL/6J) femelles adultes. Dans ce but j’ai 1) mis au point un modèle de suivi longitudinal (sur plusieurs mois) de la sécrétion de LH le jour du proestrus sur des individus uniques ; 2) analysé les effets d’une avance ou d’un retard de phase unique (10h) sur les cycles estriens et l’occurrence du pic préovulatoire de LH ; 3) analysé les effets d’avance/retard de phases chroniques (jusqu’à 9 mois) sur les cycles estriens, le pic préovulatoire de LH et la fertilité ; 4) mis au point d’injection intra-cérébro-ventriculaire (ICV) de peptides associée au suivi individuel de LH afin de proposer des méthodes de resynchronisation du pic préovulatoire de LH chez des souris soumises à des déphasages. Mes travaux montrent qu’une avance ou un retard de phase unique perturbe peu le cycle reproducteur des souris femelles jeunes tandis qu’un décalage chronique altère fortement à la fois la régularité des cycles estriens, la sécrétion préovulatoire de LH et la fertilité. Ces données fondamentales démontrent un impact négatif de la perturbation chronique des cycles journaliers sur l'axe reproducteur des souris femelles. Une extrapolation de nos données fondamentales chez la femme, notamment dans un contexte de travail posté, est à l’heure actuelle prématurée. Cependant, au vu de nos résultats, une étude prospective chez la femme est indispensableIn female mammals, cycles in reproductive function depend on both a biological clock synchronized to the light/dark cycle, and a balance between the negative and positive feedbacks of estradiol which concentration varies during ovary maturation. In women, studies report that chronodisruptive environments, notably those experienced in shiftwork conditions, may impair fertility and gestational success. The objective of this study was to explore, in female mice, the effects of shifted light/dark cycles on both the robustness of the estrous cycles and the timing of the preovulatory luteinizing hormone (LH) surge, two hallmarks of mammalian reproductive health. When mice were exposed to a single 10 h-phase advance or 10 h-phase delay, the occurrence and timing of the LH surge and estrous cyclicity were recovered at the third estrous cycle. By contrast, when mice were exposed to a chronic shift (successive rotations of 10 h-phase advance for 3 days followed by 10 h-phase delay for 4 days), they exhibited a severely impaired reproductive activity. Most mice had no preovulatory LH surge already at the beginning of the chronic shift. Furthermore, the gestational success of mice exposed to a chronic shift was reduced since the number of pups was two times lower in shifted as compared to control mice. In conclusion, this study reports that female mice exposure to a single-phase shift has minor reproductive effects whereas exposure to chronically disrupted light/dark cycles markedly impairs the preovulatory LH surge occurrence, leading to reduced fertility
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Brodin, Thomas. "Ovarian Reserve and Assisted Reproduction." Doctoral thesis, Uppsala universitet, Obstetrik & gynekologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-192998.
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Treatment success in IVF-ICSI is mainly limited by female age, but differences in ovarian reserve (OR; the remaining pool of oocytes and their quality) between individuals modify treatment prerequisites among women of similar age. OR may be assessed by OR tests (ORTs). The main aims of this work were to study menstrual cycle length (MCL), basal levels of circulating gonadotrophins, antral follicle count (AFC) and serum Anti-Müllerian hormone (AMH) levels and their associations with and prognostic capacities regarding IVF-ICSI outcome in large cohorts of unselected women. Age-adjusted MCL was positively and linearly associated with pregnancy rates (PRs), live-birth rates (LBRs) and ovarian response to controlled ovarian hyperstimulation. An MCL of >34 days almost doubled the LBR compared with an MCL of <26 days. The grouped variable ‘combined FSH and LH levels’ was superior to both individual gonadotrophin levels and the LH:FSH ratio. The highest mean PR was seen in connection with a combination of FSH <6.7 U/l with LH >4.9 U/l; PRs were lowest when FSH-LH levels were opposite to this (high-low) and intermediate when FSH-LH levels were low-low or high-high. Associations with LBR and ovarian response were similar as those for PR. AFCs and serum AMH levels were positively and log-linearly associated with PR, LBR and ovarian response. Success rates levelled out above AFC 30 or AMH 5 ng/ml. Treatment outcome was superior among women with polycystic ovaries. Among the studied ORTs, logAFC and logAMH concentration correlated most strongly. After multivariate testing, entering all studied ORTs, AMH and female age remained independently associated with LBR. AMH + AFC + age predicted both poor and excessive ovarian responses with high accuracy. Adjusting for age and oocyte yield, all ORTs remained significant for LBR, implying that ORTs also capture information on oocyte quality. In conclusion, measures of OR are strongly associated with PR, LBR and ovarian response in a log-linear fashion, and partly reflect oocyte quality. The OR spectrum is continuous, from small ‘oligofollicular’ ovaries (the low extreme) to polycystic ovaries (the high extreme). Among the studied ORTs, AMH together with age provide the most powerful basal estimate for IVF/ICSI outcome.
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Claes, Anthony N. J. "ANTI-MÜLLERIAN HORMONE IN STALLIONS AND MARES: PHYSIOLOGICAL VARIATIONS, CLINICAL APPLICATIONS, AND MOLECULAR ASPECTS." UKnowledge, 2014. http://uknowledge.uky.edu/gluck_etds/18.
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Anti-Müllerian hormone (AMH) is a homodimeric glycoprotein that is best known for its role in regression of the Müllerian duct in the male fetus. Accumulating evidence indicates that AMH also has an important role during different physiological processes after birth. In contrast to other species, relatively little is known about AMH in the horse. In chapter one, developmental and seasonal changes in serum AMH concentrations in male horses were determined, and the use of AMH for determination of retained cryptorchid testes was established. In chapter two, the interrelationship between plasma AMH concentrations, antral follicle counts (AFC), and age in mares was evaluated. Molecular and hormonal changes in the equine follicle with regard to variations in antral follicle count and follicular development were examined in chapter three. In chapter four, the effect of AFC on age-related changes in follicular parameters in light-type horse mares was examined. Peripheral AMH concentrations were significantly higher in prepubertal colts than in postpubertal stallions and varied with season in mature stallions with higher concentrations during the physiological breeding season. Furthermore, serum AMH concentrations were significantly higher in cryptorchid stallions compared to intact stallions or geldings. Circulating AMH concentrations varied widely amongst mares of the same age while the repeatability of AMH was high within and between estrous cycles. More importantly, AMH concentrations were positively associated with AFC, and this relationship increased with mare age. In addition, variations in AMH concentrations or AFC were associated with molecular differences in granulosa cells of growing follicles, and the expression of AMH and genes co-expressed with AMH in the equine follicle as well as intrafollicular AMH concentrations decreased during follicular development. Finally, the inter-ovulatory interval and length of the follicular phase is increased in aged mares with low AFC. In conclusion, AMH is a useful biomarker for cryptorchidism in stallions and ovarian reserve in mares. Furthermore, follicular function was interrelated to AFC or AMH based upon molecular differences in growing follicles, while age-related changes in follicular parameters are linked to differences in AFC.
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clifton, Mark E. "The Endocrine Basis for Reproductive Life-history Trade-offs during the Previtellogenic Resting Stage in the Yellow Fever Mosquito, Aedes aegypti." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/721.
Full textAbstract:
Juvenile hormone (JH) is the central hormonal regulator of life-history trade-offs in many insects. In Aedes aegypti, JH regulates reproductive development after emergence. Little is known about JH’s physiological functions after reproductive development is complete or JH’s role in mediating life-history trade-offs. By examining the effect of hormones, nutrition, and mating on ovarian physiology during the previtellogenic resting stage, critical roles were determined for these factors in mediating life-history trade-offs and reproductive output. The extent of follicular resorption during the previtellogenic resting stage is dependent on nutritional quality. Feeding females a low quality diet during the resting stage causes the rate of follicular resorption to increase and reproductive output to decrease. Conversely, feeding females a high quality diet causes resorption to remain low. The extent of resorption can be increased by separating the ovaries from a source of JH or decreased by exogenous application of methoprene. Active caspases were localized to resorbing follicles indicating that an apoptosis-like mechanism participates in follicular resorption. Accumulations of neutral lipids and the accumulation of mRNA’s integral to endocytosis and oocyte development such as the vitellogenin receptor (AaVgR), lipophorin receptor (AaLpRov), heavy-chain clathrin (AaCHC), and ribosomal protein L32 (rpL32) were also examined under various nutritional and hormonal conditions. The abundance of mRNA's and neutral lipid content increased within the previtellogenic ovary as mosquitoes were offered increasing sucrose concentrations or were treated with methoprene. These same nutritional and hormonal manipulations altered the extent of resorption after a blood meal indicating that the fate of follicles and overall fecundity depends, in part, on nutritional and hormonal status during the previtellogenic resting stage. Mating female mosquitoes also altered follicle quality and resorption similarly to nutrition or hormonal application and demonstrates that male accessory gland substances such as JH III passed to the female during copulation have a strong effect on ovarian physiology during the previtellogenic resting stage and can influence reproductive output. Taken together these results demonstrate that the previtellogenic resting stage is not an inactive period but is instead a period marked by extensive life-history and fitness trade-offs in response to nutrition, hormones and mating stimuli.
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Li, Christopher I.-Fu. "Relationship between hormonal, reproductive, anthropometric, and lifestyle factors and risk of lobular and ductal breast cancer /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/10932.
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Jackson, Barbara Ann, and n/a. "A study of baby boomer women and their expectations of menopause." University of Canberra. Professional & Community Education, 1996. http://erl.canberra.edu.au./public/adt-AUC20060801.142823.
Full textAbstract:
This is a study of a generation of women who are about to enter the
climacteric period of their life, the menopause. Born between the years
1946 and 1956 they have been the object of continuous scrutiny by various
interest groups. Because they are seen to be unique, many acronyms and
titles, the most noted being the 'Baby Boomers' have been attached to
them. The women of this generation have been classed as a Very active'
generation, leaving a clear mark on society and the re-emerging women's
movement. As they near menopause they are approaching a stage that
could be seen as their last reproductive transition. For many women
there is no cultural ritual, nor a single story to guide them through this
period They are however not without advice. The 'big voices' of the
drug companies, the medical system and the media, all tender their
guidance as the dominant voice. These women have been told what to
do by experts throughout their whole lives. It seems 'expert advice' on
their reproductive phases have been penned mostly by men in the
interests of treating, controlling and saving them. Control of their body
remains a key struggle, both physically and linguistically.
The purpose of the research was to study the expectations of this
post-war, Baby Boom generation of menopause. The study shows that
some women have made decisions to embrace non-medical help and
accept menopause as an inevitable transition, while others are willing to
consider medical help to enhance their 'quality of life '. Believing it is
time to look after themselves, it seems many women will take a
pragmatic view and accept medical opinion that the menopause is a
deficiency disease, even if this requires them to become part of the
consumer driven/drug company push for a 'symptom free' menopause.
They wish to remain untroubled and express a willingness to do
whatever they need to fulfil this. Their fervent hope is that the
menopause will not upset their career, family or 'life'. Consequently a
large majority of these women will think about or actively pursue
hormone replacement therapy.
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Bas, Santiago. "IMPROVING REPRODUCTIVE PERFORMANCE THROUGH THE DEVELOPMENT OF A DAIRY HERD INDEX, INTRAUTERINE HORMONE DELIVERY OR INSEMINATION TECHNIQUE IN LACTATING COWS." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365425549.
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Hudecova, Miriam. "Reproductive and Metabolic Consequences of the Polycystic Ovarian Syndrome." Doctoral thesis, Uppsala universitet, Institutionen för kvinnors och barns hälsa, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-123248.
Full textAbstract:
Polycystic ovary syndrome (PCOS) is a complex clinical condition characterized by hyperandrogenism and chronic oligo/anovulation. Infrequent ovulation and metabolic alterations in women with PCOS are associated with subfertility and probably increased miscarriage rates compared with normal fertile women. The overall risk of developing type 2 diabetes and impaired glucose tolerance (IGT) is three- to sevenfold higher in PCOS women, and the onset of glucose intolerance seems to occur at an earlier age than in healthy controls. Women with PCOS also have several risk factors for cardiovascular disease, although it is unclear whether they actually experience more cardiovascular events than other women. Very few studies assessing the long-term reproductive and metabolic consequences in older women with previously confirmed PCOS have been conducted. In this long-term follow-up of women with PCOS, 84 women with a diagnosis of PCOS between 1987 and 1995 and age at the follow-up > 35 years and an age-matched population-based group of control women participated. Data on reproductive outcome, ovarian reserve, endothelial function, insulin sensitivity and beta-cell function were collected. According to our results most women with PCOS had given birth and the rate of spontaneous pregnancies was relatively high. The rate of miscarriages was not increased in PCOS patients and the ultrasound findings together with increased levels of anti-müllerian hormone suggested that their ovarian reserve is superior to women of similar age. PCOS women displayed signs of endothelial dysfunction, but this was largely due to the increased prevalence of independent risk factors for cardiovascular disease such as increased BMI, triglycerides and blood pressures. IGT and type 2 diabetes occurred more often in PCOS women. Free androgen levels and beta-cell function decreased over time whereas insulin sensitivity remained unchanged. Obesity at young age and progressive weight-gain rendered them more prone to be insulin resistant at the follow-up. Beta-cell function was increased in PCOS women in comparison with control subjects but declined over time. Independent of PCOS phenotype at the index assessment and persistence of PCOS symptoms at the follow-up investigation, premenopausal women with PCOS had lower insulin sensitivity and increased beta cell function in comparison with control subjects. Conclusion: The long-term reproductive outcomes of PCOS are similar compared to women with normal ovaries. Although symptoms and androgen levels are normalized over time, women with PCOS continue to display reduced insulin sensitivity and increased beta-cell function and they also have an increased risk of IGT and type 2 diabetes.
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Roegner, Michael Anthony. "Re-analysis of the women's health initiative: breast cancer and its associations with post-menopausal hormone replacement therapy, reproductive history, and lifestyle." Thesis, Boston University, 2012. https://hdl.handle.net/2144/12607.
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Thesis (M.A.)--Boston University
PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.After the publication of the principal, or primary, results from the WHI, there were a large number of surprises in the findings, as well as a fair amount of controversy surrounding the conclusions. Because of the expansive breadth and importance of this study, a comprehensive compiling of all of the important re-analyses of the study, followed by more analyses, seemed pertinent to the scientific community. The entirety of the WHI focused on a large variety of chronic illnesses that post-menopausal women face but this paper will focus on the modifiable and non-modifiable risk factors important in the development and etiology of breast cancer. An in-depth review of the principal results regarding breast cancer from the WHI was undertaken, followed by a large and comprehensive compilation, review, and analysis of all the secondary analyses of the WHI principal data with the intent of verifying or disqualifying, via a mass of statistical analyses and long term observational studies, the conclusions drawn by the WHI investigators. After the aforementioned steps were taken, it was concluded by the author of this paper that the combined post-menopausal hormone regimen, as seen in the WHI Combined Hormone Trial, does pose serious risks in terms of increasing the hazard ratio for developing breast cancer, even for a short period of use, especially if multiple bouts are undertaken, confirming the conclusions from the WHI. Secondly, it was concluded by the author of this paper that the use of unopposed estrogen during a women's postmenopausal years does not increase one's risk for the development of breast cancer, only if initiated at least 5 years beyond menopause. These results were in major disagreement with the results from many other large studies, including the Million Women Study and the Collaborative Re-Analysis. The WHI Dietary Modification Trial was a huge success, despite the conclusions from the WHI attesting otherwise. In the Dietary Modification Trial, the WHI reasoned that the trial had no real effect due to a p-value of 0.07, despite overwhelming statistical and clinical evidence that it was indeed having a real effect. Implementing a low fat diet and increasing fruit, grain, and vegetable intake will lower a post-menopausal woman's hazard ratio for developing breast cancer and be further recommended to any woman, at any age. Lastly, the WHI principal results from their physical activity analysis concluded that regular physical activity will decrease a woman's hazard ratio for the development of breast cancer and this conclusion was reaffirmed by a large number of secondary analyses. Regular physical activity, assessed from nearly every angle, of any type, but regularly, will reduce the risk for the development of breast cancer, manifested through, for example, reductions in serum estradiol and body mass index. This lengthily study readily and efficiently addressed risk factors for breast cancer development and provided a large volume of data for future analysis as well. The conclusions made in this paper, as previously eluded to, make very clear the risk of combined hormone use and the many benefits of physical activity, for example. With these conclusions, both woman and physicians can harness the knowledge here and implement changes within their own life or how they practice and approach post-menopausal women's health, leading to longer and healthier years for post-menopausal women.
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Tyminski, John P. "Androgen receptors in the bonnethead shark, Sphyrna tiburo : cDNA cloning and tissue-specific expression in the male reproductive tract." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002128.
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Dalle, Luche Greta. "Validation and use of a HPLC-MS/MS method for the analysis of multiple steroid hormones in humpback whale blubber." Thesis, Griffith University, 2020. http://hdl.handle.net/10072/392397.
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This thesis describes the novel use of multiple steroid hormone analysis to investigate and gain understanding of previously unknown aspects of the endocrinology and reproductive biology of the Southern Hemisphere humpback whale (Megaptera novaeangliae). Steroid hormones are a class of structurally related molecules that function as messengers in a variety of important physiological processes (e.g. salt homeostasis, immune system, sexual development and reproductive cycles). A number of endogenous steroid hormones have been identified as critical for reproduction (e.g. androgens, progestogens, oestrogens) and stress response (e.g. corticosteroids) in mammals. Understanding the species-specific roles and baseline levels of endogenous steroid hormones enable these compounds to be used as biomarkers of reproductive status and stress exposure. The use of steroid biomarkers for these purposes promises to be extremely advantageous in cetacean species, since other approaches often require increased time and resources. However, the collection and interpretation of steroid hormone data in the humpback whale is currently limited by methodological issues (e.g. challenging sampling, difficult comparison between sample types, analytical approach restricted to single hormone analysis), and by a general lack of detailed knowledge of the humpback whale endocrine system.
Collection of biological samples from cetaceans is inherently difficult. In particular, free-swimming individuals of baleen whale species, including humpback whales, cannot be kept in captivity, nor they can be immobilised for sampling. Contemporary studies have demonstrated that steroid hormones analysis is viable in baleen species through the use of remotely collected tissues and fluids (i.e. faeces, blow, blubber). The seasonal migration of the humpback whales from the Antarctic feeding areas to the tropical breeding grounds, however, imposes further restrictions in regard to sample types and timing of collection. To date, blubber is the only matrix employed for steroid analysis in this specie and comprehensive seasonal steroid hormone changes have not being studied.
Blubber is a lipid-rich tissue, able to sequester traces of steroid hormones from circulation. This is advantageous as multiple types of steroid hormones are likely to be present in this tissue. However, steroid hormones in blubber, particularly those at trace levels, can only be quantified by using sensitive techniques that need to accommodate the presence of lipids in the matrix. Enzyme immunoassay (EIA) is typically used for steroid hormone analysis in complex matrices, as it requires minimal sample preparation. Although EIA provides high sensitivity, its precision can suffer due to the indirect nature of the measurements and by the possibility of cross-reactivity. A significant disadvantage of employing EIAs for the investigation of species-specific endocrinology is that each EIA quantifies only a single steroid hormone, or a single class of steroid metabolites in its ensemble. Single steroid hormone measurements can be misleading, as steroid hormones act in concert. The same steroid hormone can have different roles and increase or decrease in concentration to accommodate different biosynthetic pathways (e.g. acting as an active metabolite, or as a precursor to or degradation product from other steroids). Liquid chromatography coupled with tandem mass-spectrometry (LC-MS/MS) represents an alternative to EIAs, as it can provide accurate and precise quantification of multiple steroid hormones from the same sample portion. Major issues in LC-MS/MS methods include the coelution of multiple analytes or the interference of matrix components, which can sometimes be resolved only through a trade-off between analyte resolution and sensitivity. These challenges can however be identified prior to the analysis, and overcome, at least partially, by optimising the sample extraction and cleanup. This thesis aimed to adapt and validate a LC-MS/MS method for extracts of humpback whale blubber, and to evaluate use of multiple steroid hormone measurements in relation to reproductive status and possible stress exposure from free-ranging individuals.
Blubber samples from stranded humpback whale carcasses were initially employed to assess the applicability, scope, and repeatability of a LC-MS/MS method for the analysis of multiple steroid hormones (Chapter 2). The method, initially developed for bottlenose dolphin (Tursiops truncatus) blubber, proved to be applicable to the comparatively lipid-rich humpback whale outer blubber. Levels of five corticosteroids and six reproductive steroids (including androgens, progestagens and oestrogens) were determined in humpback whale blubber, and ten of these analytes could be quantified with high accuracy (error on amended samples < 15%) and repeatability (percent standard deviation < 15%). The multi-steroid hormone profiles obtained by the stranded carcasses were also investigated as potentially indicative of the endocrinological responses of some of the whales to stress exposure. Subsequently, the LC-MS/MS method was applied to biopsy extracts from freeswimming humpback whales collected at two time points of the whale breeding season over multiple years. The application of this methodology to live biopsies resulted in a smaller number of analytes detected, predominantly as an effect of the corticosteroid analytes being lower in concentration or undetectable in these samples. The quantified steroid hormones provided, however, novel insights into endocrinology and reproductive biology of female (Chapter 3) and male (Chapter 4) humpback whales.
In Chapter 3, we show how the use of a previously validated pregnancy concentration threshold for the single hormone progesterone failed to detect any pregnant females based on LC-MS/MS analysis of blubber extracts from 23 females sampled while approaching the breeding grounds. However, by considering multiple steroid profiles including androgens and cortisol, we suggest that relatively high blubber concentrations of androstenedione may distinguish pregnant individuals during the last month of gestation. This hypothesis is supported by reference to steroid hormone measurements through pregnancy in evolutionarily related mammal species, although further work (e.g combining photo identification) is required to provide conclusive evidence. In addition, the same previously validated progesterone threshold resulted in an unexpectedly low proportion of pregnant females (3%) from among 29 females departing the breeding grounds. This prompted the suggestion of a new lower progesterone concentration threshold for assignment of early pregnancy status.
In Chapter 4, the seasonal variations in blubber steroid hormone concentration in males are examined through the breeding season. Lowering of testosterone during the expected peak in reproductive activity suggests asynchronicity between blubber testosterone levels and male fertility. Correlation analyses among multiple hormone couples are used to postulate the changes in biosynthetic pathways behind the large interseasonal variations in steroid concentrations. These large intra-season variations in blubber androgens and a contrasting relationship with cortisol across the migration, encourages further investigation on the effects of age and sexual maturity on concentrations of these two hormones. This is necessary before they can be used as biomarkers for reproductive status or stress exposure.
An application of how some of the multi-hormone information can be used to improve humpback whale monitoring is provided in Chapter 5. Early and late pregnancy diagnoses as formulated in Chapter 3, are combined with body condition information simultaneously measured in the same female individuals. Superior body condition among late-pregnant female corroborated previous observations that females would increase their feeding opportunities before parturition in order to support, as capital breeders, the combined energetic cost of migration and lactation. In contrast, no relationship was found between whales identified as early pregnant and their body condition compared to the rest of the migrating females. These results suggest that body condition and fertility might not be directly related during the breeding season. Instead, annual winter-feeding efficiency might be more important than accumulated energy stores in guaranteeing the annual reproductive success in females of this species.
Overall, by analysing for a larger suite of steroid compounds and focusing on a comparatively less studied period of the migration, this work revealed some limitations of the current methodology used to measure steroid hormones in humpback whales. These findings enhance our knowledge of the humpback whale endocrine system and provide new approaches for the diagnostic use of steroid hormones profiles in free-swimming humpback whales.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Bowers, Hannah Elizabeth, and Jennifer Hall. "THE EFFECTS OF ESTROGEN-INDUCED STROMAL CELL EFFECTORS, OSTEOPONTIN AND VIMENTIN, ON CHLAMYDIA INFECTIONS IN A NON-POLARIZED CELL CULTURE MODEL." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/98.
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Chlamydia is the most reported sexually transmitted infection in the US and is caused by the obligate intracellular bacterium Chlamydia trachomatis. Typically, this presents as a lower genital tract infection (cervicitis or urethritis), but can ascend to the upper genital tract, causing pelvic inflammatory disease, tubal infertility, epididymitis, or ectopic pregnancy. While chlamydia infections can be cured with a single-dose oral antibiotic, repeat infections are common and having multiple chlamydial infections increases a woman’s risk of developing serious chronic conditions. Previous research has shown that estrogen has a positive effect on C. trachomatis infections—an important finding, connecting fluctuating estrogen levels in females to variance in pathogenesis.The mechanism behind this hormonal influence remains unknown; however, previous work in our laboratory indicates that estrogen-stimulated stromal cell effectors play a role in enhancing C. trachomatis infections in a polarized endometrial epithelial Ishikawa (IK)/stromal (SHT-290) cell co-culture model. Specifically, our data indicate that estrogen exposure stimulates osteopontin and vimentin release from stromal cells in co-culture with endometrial epithelial cells. Furthermore, we noted that Chlamydia-infected, polarized Ishikawa cells exposed to a combination of recombinant osteopontin and estrogen released significantly more infectious chlamydia than cultures exposed to estrogen alone. Most tissue culture models being used today employee non-polarized cells. Given the fact that epithelial cell polarization is known to impact C. trachomatis serovar E development, in the current study we sought to determine if the estrogen-induced stromal cell effectors, osteopontin and vimentin, affect C. trachomatis viability and infectivity in non-polarized Ishikawa cells. Non-polarized Ishikawa cells were exposed to osteopontin or vimentin in the presence or absence of estrogen, infected with C. trachomatis serovar E, and collected for examination of chlamydial infectivity and progeny production. Our initial data show that osteopontin and vimentin impact chlamydial progeny production in a concentration dependent fashion, with higher concentrations of recombinant effectors +/- estrogen significantly decreasing progeny production. These data suggest that polarization of host cells influences the way hormone-stimulated effectors interact with the cell to impact on chlamydial infection. Future research goals are to explore other stromal effectors such as fibronectin with estrogen and to study the cell signaling mechanism osteopontin and vimentin use to affect chlamydial infections in polarized epithelial cell cultures.
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Schirar, Alain. "L'anoestrus de lactation chez la brebis Préalpes du sud : reprise de l'activité gonadotrope hypothalamo-hypophysaire et de l'activité ovarienne." Paris 6, 1986. http://www.theses.fr/1986PA066250.
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Le but de l'étude a été de rechercher les mécanismes physiologiques de l'action inhibitrice de la lactation sur la reproduction en utilisant les brebis "Préalpes du sud" comme modèle expérimental que la durée de l'anoestrus postpartum dépend essentiellement des facteurs nerveux centraux qui contrôlent la sécrétion pulsatile de lh. L'allaitement retarde le rétablissement de cette sécrétion pulsatile par un mécanisme qui semble impliquer les opiaces endogènes déchargés au moment des tétées. Les faibles différences observées dans la durée de l'anoestrus postpartum et de lactation résultent en partie de l'influence modulatrice et régulatrice du complexe utéroovarien.
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Wihlbäck, Anna-Carin. "Ovarian hormones and effects in the brain : studies of neurosteroid sensitivity, serotonin transporter and serotonin2A receptor binding in reproductive and postmenopausal women." Doctoral thesis, Umeå universitet, Obstetrik och gynekologi, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-365.
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Background: Estrogen has been reported to enhance well-being and quality of life during the climacteric phase. In women with an intact uterus estrogen treatment is always combined with progestins in order to protect the endometrium from hyperplasia and malignancies. However, in certain women the addition of progestins causes cyclicity in negative mood symptoms and physical symptoms similar to those encountered during ovulatory cycles in women with premenstrual dysphoric disorder (PMDD). The ovarian hormones estradiol and progesterone have profound effects on a number of neurotransmitter systems in the brain, such as the gamma aminobutyric acid (GABA) system and the serotonergic system. Progesterone metabolites, such as allopregnanolone and pregnanolone (also referred to as neurosteroids) modify the GABAA receptor in the central nervous system (CNS) and enhance GABAergic inhibitory transmission. Neurosteroid sensitivity in human studies can be studied by saccadic eye movement measurements using pharmacodynamic challenges with pregnanolone. Altered neurosteroid sensitivity has been suggested as a possible contributory factor to the progesterone/progestin-induced adverse mood effects of hormone replacement therapy (HRT). There is also evidence of estrogen treatment affecting the serotonergic system in postmenopausal women, although progestin addition has been less well studied. Aims and method: The aim was to investigate whether the negative mood symptoms experienced during the progestin or progesterone phase of HRT were associated with changes in neurosteroid sensitivity, or changes in platelet serotonin uptake site (transporter) and serotonin2A (5-HT2A) receptor binding. The intention was also to investigate whether hormonal changes during the normal menstrual cycle affect these peripheral serotonergic parameters. Postmenopausal women with climacteric symptoms were given HRT in two randomized, double-blinded, placebo-controlled crossover studies. The women received 2 mg estradiol (E2) continuously during 28- day cycles. Synthetic progestins or natural progesterone were added sequentially during the last 14 days, and compared to a placebo addition. Before treatment, as well as during the last week of each treatment cycle the pharmacodynamic response to pregnanolone was assessed using saccadic eye movement measurements. Throughout the studies daily symptom ratings were made. In the study regarding synthetic progestins, platelet serotonin transporter and 5-HT2A receptor binding were assayed before entering the study, as well as during the last week of each treatment cycle. In the study on reproductive women, blood samples were collected for analysis of platelet serotonin transporter and 5-HT2A receptor binding at six different points in time during the menstrual cycle. Results and conclusion: The addition of synthetic progestins to estrogen treatment increased negative mood symptoms and physical symptoms, whereas positive symptoms decreased. The addition of progestins also increased the sensitivity to pregnanolone. The addition of natural progesterone to estrogen treatment increased the sensitivity to pregnanolone. However, in this study the pregnanolone sensitivity was enhanced also during estrogen treatment. Women expressing cyclicity in negative mood symptoms were more sensitive to pregnanolone than women without symptom cyclicity. Thus, it is evident that mood deterioration during HRT is associated with altered neurosteroid sensitivity. Platelet serotonin transporter and 5-HT2A receptor binding did not change during the different treatment conditions in HRT. Thus, we were unable to explain the negative mood changes of HRT by use of these peripheral serotonergic parameters. In the study on reproductive women however, it was clear that the serotonergic variables did change during the menstrual cycle. Binding to the serotonin transporter was higher in the late follicular phase than in the ovulatory, early luteal or mid-luteal phases. Binding to the 5-HT2A receptor was higher in the early follicular phase and the early luteal phase than in the mid-luteal phase. These findings may provide a link between the ovarian steroids, and the GABAergic and serotonergic neurotransmitter systems, which in turn, could explain part of the specific vulnerability that women have for the development of adverse mood effects during HRT, mood and anxiety disorders and for the deterioration of mood so frequently seen during the luteal phase.
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Bode-Rhoads, Michelle Lynn. "Regulation of the growth hormone receptor, insulin-like growth factor (IGF) I and IGF binding protein 2 in reproductive tissues of dairy cattle during lactation and associated effects on fertility." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p3164490.
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Wirmer, Andrea [Verfasser], Ralf [Akademischer Betreuer] Heinrich, Gabriele [Akademischer Betreuer] Flügge, and Andreas [Akademischer Betreuer] Stumpner. "Modulatory effects of nitric oxide and juvenile hormone on the control of reproductive behavior in female Chorthippus biguttulus / Andrea Wirmer. Gutachter: Ralf Heinrich ; Gabriele Flügge ; Andreas Stumpner. Betreuer: Ralf Heinrich." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2010. http://d-nb.info/1042841691/34.
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Dauphin-Villemant, Chantal. "Etude du fonctionnement de l'interrenale (corticosurrenale) chez la femelle du lezard vivipare jacquin : evolution au cours du cycle annuel d'activite et de reproduction." Paris 6, 1987. http://www.theses.fr/1987PA066329.
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Yvorra, Alain. "Croissance folliculaire et developpement du corps jaune chez le lezard vivipare, lacerta vivipara jacquin : evolution au cours du cycle sexuel et analyse des mecanismes de regulation." Paris 6, 1986. http://www.theses.fr/1986PA066270.
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Hannesdottir, Solveig Gudrun. "Immunosterilisation affecting the functional level of reproductive hormones." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269686.
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Benki, Sarah Frances. "The relationship between female reproductive hormones and HIV-1 /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/11517.
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Narayanaswamy, Shakunthala. "Physiological studies investigating the actions of novel reproductive hormones." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/33792.
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Infertility is becoming increasingly more common, affecting 1 in 6 couples in the UK and an estimated 48.5 million couples worldwide. Although there are a number of hormonal treatments, there has been very little advance in new treatments in the last decade. However, assisted reproductive therapies including in vitro fertilisation (IVF) are being more commonly used and in fact 2% of babies were conceived in the UK through IVF in 2012, although the average pregnancy rate per cycle has remained stable at only 20% for several years. Therefore, there is a huge scope for developing new treatments to help with the rising problem of infertility. Kisspeptin is a hypothalamic hormone that was associated for the first time with reproduction in 2003 and is now emerging as a possible novel future therapeutic for reproductive and fertility disorders. Kisspeptin signalling is vital for normal reproductive function and critically regulates GnRH secretion in response to metabolic and environmental cues. Previous research studies have shown that kisspeptin can be administered safely to humans with no side effects and therefore, my research builds on this previous work. I have focused on investigating how best to optimise the use of kisspeptin for future therapy, by firstly examining which isoform of kisspeptin is more potent and how this compares to GnRH (a current treatment modality). Secondly, I investigated whether continuous subcutaneous administration of kisspeptin would be a viable treatment modality, as in the future kisspeptin could be administered in a subcutaneous pump device and managed at home by the patient. I also investigate how baseline oestradiol levels may influence the gonadotrophin response to kisspeptin. Lastly, I investigate how kisspeptin interacts with two other neuropeptides to affect gonadotrophin secretion, by coadministration of them in healthy males.
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MacLennan, A. H. "The role of the hormone relaxin in human reproduction." Thesis, University of Glasgow, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372418.
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Liu, Han-Ken. "Effects of feed restriction and duration of the reproduction period on reproduction hormones and follicular development in broiler breeder hens." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1092249440.
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Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xvii, 275 p.; also includes graphics (some col.) Includes bibliographical references (p. 239-275). Available online via OhioLINK's ETD Center
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Philipon, Patrick. "Immunisation active contre l'androsténédione et taux d'ovulation chez la brebis : analyse physiologique et zootechnique." Tours, 1988. http://www.theses.fr/1988TOUR4008.
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