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1
Stirling, David. "Functional regulation of the corpus luteum." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/19321.
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2
Smith, George W. "Local regulators of corpus luteum function /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9717154.
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3
Sen, Aritro. "Cellular mechanisms of luteal regression in the bovine corpus luteum (CL)." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4298.
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Thesis (Ph. D.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains xvi, 155 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 103-152).
4
Nicklin, Leah Theresa. "Functional development of the bovine corpus luteum." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416289.
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5
Shelton, K. "Endocrine studies on the bovine corpus luteum." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376416.
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6
Rae, Michael T. "Progesterone binding in the bovine corpus luteum." Thesis, University of Edinburgh, 1996. http://hdl.handle.net/1842/21476.
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This project was designed to examine the intracellular location of progesterone in bovine luteal cells. These experiments demonstrated the existence of a particulate membrane fraction of luteal cells where much of the endogenous progesterone was located. Results suggest an association between this fraction and the plasma membrane. Moreover, it was shown that these membranes were able to bind exogenous radiolabelled progesterone in a highly specific manner. Other steroids, precursors etc. were bound poorly. Thus, the experiments herein describe the characterisation of this novel progesterone binding site, its distribution in the cells of the bovine corpus luteum and preovulatory follicle, and attempts to purify and identify the progesterone binding protein. Results from these experiments indicated that the progesterone binding site investigated was distinct from classical genomic progesterone receptors. This non-classical progesterone binding protein (NCP4-BP) was found in both large and small luteal cells of the corpus luteum, though levels were greater in large cells. NCP4-BP was also found in the theca and granulosa cells of the preovulatory follicle. Binding characteristics of the NCP4-BP were determined, and partial purification achieved. Results demonstrate that progesterone binding was not due to (i) steroid metabolizing enzymes (ii) non-specific intercalation of steroid into bi-layer membranes or (iii) the genomic progesterone receptor. Studies suggest that the binding site studied may represent a membrane located progesterone receptor with a potential role in the regulation of luteal function in cows.
7
Rodger, Faye Elizabeth. "Cellular interactions in the human corpus luteum." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/22597.
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The corpus luteum is a transient endocrine gland which is essential for the maintenance of early pregnancy in mammals, however the physiological mechanisms which control luteal lifespan are poorly understood. The aim of this thesis is to investigate potential control points in luteal maintenance and regression by studies utilising human tissues from throughout the luteal phase and in simulated early pregnancy. In particular, the roles of luteal growth and angiogenesis, apoptosis and immune cells are examined. Results of these studies indicate that although angiogenesis is maximal in the early luteal phase, growth of blood vessels does not vary during luteal maintenance and regression. Similarly, although the apoptotic protoncogenes bcl-2 and bax are present in the human corpus luteum, expression of these factors remains constant as luteal function changes. Leukocytes are present throughout the luteal lifespan and local cytokine production may be important in causing the ingress of immune cells which is observed during luteal regression. Cells of steroidogenic, vascular and immune cell compartments of the human corpus luteum may interact in complex ways to bring about changes in the function and structure throughout the lifespan of the gland.
8
Teschner, Dominik. "Zur Charakterisierung sonographischer Befunde am Corpus haemorrhagicum und Corpus luteum der Stute /." Berlin : Mbv, 2008. http://d-nb.info/991429222/04.
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9
Brockhan-Lüdemann, Maren. "Farbdopplersonographische Untersuchungen zur Funktion des bovinen Corpus luteum." Hannover Bibliothek der Tierärztlichen Hochschule Hannover, 2010. http://d-nb.info/1000021076/34.
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10
Amelkina, Olga. "Corpus luteum of the domestic cat and lynx." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17451.
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Der Gelbkörper (corpus luteum, CL) ist eine transitorische Drüse, die im Ovar nach der Ovulation gebildet wird und durch ihre Progesteron-(P4)-Produktion die Trächtigkeit unterstützt. Bei allen bisher untersuchten Säugetieren endet die sekretorische Aktivität der CL mit dem Ende der Trächtigkeit oder Laktation, danach werden die CL abgebaut. Der Zyklus von Katzenartigen, wie etwa der Hauskatze, folgt dem gleichen Muster. Anders verläuft der Zyklus bei Luchsen. Beim Eurasischen Luchs (Lynx lynx) und beim Pardelluchs (Lynx pardinus) persistieren die CL nach der Geburt für mehr als zwei Jahre und sezernieren weiter P4. Die vorgestellte Arbeit sollte die Funktion persistierender (per) CL im Luchs untersuchen und die Fortpflanzung von Katzen weiter aufklären. Dazu wurden grundlegende histologische und hormonelle Aspekte der Lutealphase analysiert und der Einfluss des apoptotischen Systems sowie die Rezeptivität gegenüber Steroiden bei der Regulation der CL-Funktion betrachtet. Die CL von Hauskatzen und Luchsen wurden histomorphologisch unterteilt. In allen Proben wurden intraluteales P4 und Östrogene bestimmt. Weiterhin wurde die mRNA- und, wenn möglich, die Proteinexpression der proapoptotischen Faktoren BAX, Caspase-3, FAS, Tumor necrosis factor (TNF), TNF Rezeptor 1 (TNFRSFA1) und der Überlebensfaktoren (BCL2, TNFRSFB1), sowie des Progesteronrezeptors (PGR), der PGR-Membrankomponente (PGRMC) 1 und 2, des Östrogenrezeptors (ESR) 1 und 2, des G-Protein-gekoppelten Östrogenrezeptors 1 (GPER1) und des Androgenrezeptors (AR) gemessen. Die Ergebnisse weisen darauf hin, dass die Lutealphase der Hauskatze durch FAS, Caspase-3 und die TNF Rezeptoren 1 und 2 reguliert sein könnte. Steroide könnten über ihre Rezeptoren PGR, PGRMC1 und PGRMC2, ESR1 und AR wirken. Die physiologische Persistenz der CL beim Luchs könnte über BCL2, FAS, TNFRSFB1, PGRMC1, PGRMC2, ESR1, GPER1 und AR vermittelt werden.Corpus luteum (CL) is a transitory gland which forms in the ovary after ovulation and supports the pregnancy with its production of progesterone (P4). In all mammals studied so far, the CL loses its secretory activity after pregnancy and regresses from the ovary. The feline luteal cycle follows the same pattern, and CL of the domestic cat functionally and structurally regress after lactation. However, the story is different for the lynx. In the Eurasian (Lynx lynx) and Iberian (Lynx pardinus) lynx, CL persist after parturition, weaning and for up to two years, still retaining their ability to secrete P4. Current work was initiated to understand the control of unusual persistent (per) CL in lynx and to learn more about feline reproduction in general. For this, studies on the basic histological and endocrinological aspects of the feline luteal phase, as well as potential involvement of systems of apoptosis and steroid receptivity in the CL regulation were performed. Collected CL from domestic cats and lynx were classified based on their histomorphology. In all samples, intraluteal P4 and estrogens were measured. Moreover, mRNA and where possible protein levels were determined for pro-apoptotic BAX, caspase-3, FAS, tumor necrosis factor (TNF), TNF receptor 1 (TNFRSFA1), pro-survival BCL2, TNFRSFB1, and for progesterone receptor (PGR), PGR membrane components (PGRMC) 1 and 2, estrogen receptors (ESR) 1 and 2, G protein-coupled estrogen receptor 1 (GPER1) and androgen receptor (AR). The results suggest that the luteal phase of the domestic cat is potentially regulated by caspase-3, FAS, TNFRSF1A, TNFRSF1B, and by actions of steroids via PGR, PGRMC1, PGRMC2, ESR1 and AR. Physiological persistence of Iberian lynx CL might be mediated by BCL2, FAS, TNFRSFB1, PGRMC1, PGRMC2, ESR1, GPER1 and AR. Current work indicates profound differences between the CL function and regulation in domestic cats and lynx, and promotes a highly species-specific approach in reproduction studies.
11
Prokopiou, Sotiris. "Integrative modelling of angiogenesis in the bovine corpus luteum." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13139/.
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The corpus luteum (CL) is a tissue formed from the remnants of an ovulated follicle in the ovary, and it produces the progesterone needed for a healthy pregnancy. CL growth is highly dependent on a growing nutrient supply, and can be compared with the most aggressive vascular tumours. Angiogenesis, the growth of new blood vessels from existing ones, plays a key role in the growth and function of the CL. Inadequate angiogenesis has been linked to infertility in cows. The CL is composed of several vascular(e.g. endothelial cells (ECs), pericytes (PCs)), and avascular (e.g. luteal cells (LCs), immune cells) cell types, and several pro-angiogenic factors (e.g. Fibroblast Growth Factor 2, FGF2) found to be important in the angiogenic process. The objective of this thesis is to shed light on the cellular and extracellular level determinants of angiogenesis in the bovine CL. We begin with the relevant biological and mathematical literature in Chapter 1. In Chapter 2, an ordinary differential equation model of CL growth is introduced. We assume that the CL volume is a continuum of three cell types, ECs, LCs, and stromal cells (such as PCs). The fourth variable in the model, FGF2, enhances the EC proliferation rate. The model is able, by varying parameters such as the maximal proliferation rate of the ECs, to distinguish cases where the CL shifts from a ‘normal’ to a ‘pathological’ growth. In Chapter 3, we present in vitro CL published and novel studies from Robinson’s Lab. Preliminary results demonstrate interesting endothelial and pericyte behaviours regarding cell aggregation and sprout formation, which are the motivation for the next two Chapters. In these experimental studies, all the CL cell types were incorporated in the same in vitro culture, hence providing a closer approximation to the in vivo environment compared to other in vitro cultures which use only a single cell type (mainly ECs). However, this complicates matters in terms of distinguishing cell behaviours and factors which contribute on the overall cell dynamics. Therefore, in the Chapters 4 and 5 we use data from literature. In Chapter 4, by using the Cellular Potts Model (CPM) framework, we focus on EC-PC interactions, and particularly on the mechanism which is responsible for the EC growth inhibition. Our model incorporates two possible mechanisms for inhibition. That is, the mechanical cell-cell contact inhibition, and the inhibition mediated from diffusive TGF-b secreted once the two cell types come in contact. Interestingly, our model results suggest that the effective range of TGF-b is a crucial determinant of the degree of EC growth inhibition. Chapter 5, by using a CPM, is devoted to sprouting angiogenesis (the formation of new blood vessel). The dynamic interchange between stalk and tip EC phenotype is incorporated through the Notch signalling pathway, with the leading tip cell moving up macrophage-mediated VEGFA gradients in a non-uniform matrix environment. The model reproduces phenomena in sprouting angiogenesis, including sprout morphology, tip competition, and explains knockout experiments on the Notch signalling pathway. Finally, we close with Chapter 6 where we summarise the ain results from each chapter and propose model extensions for future directions.
12
Gomes, Tiago João da Silva. "Equine corpus luteum vascular evaluation by power-doppler ultrasound." Bachelor's thesis, Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária, 2008. http://hdl.handle.net/10400.5/898.
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Dissertação de Mestrado Integrado em Medicina VeterináriaA ecografia com recurso Doppler é uma tecnologia emergente que tem demonstrado ter potencial para melhorar as capacidades de diagnóstico dos veterinários de equinos. Esta tecnologia baseia-se nos príncipios do Doppler, onde as frequências de ultra-som estão dependentes do movimento dos eritrócitos dentro dos vasos sanguíneos. A função do Corpo Lúteo (CL) está dependente do aporte sanguíneo, o qual fornece não só percursores esteroides mas também permite libertação de progesterona (P4) na circulação sistémica. Desta forma uma técnica Doppler mais sensível, o modo Power Doppler, foi utilizada para avaliar uma possível relação entre as características do Corpo lúteo e a concentração da progesterona plasmática. Para este estudo nove éguas (n=9) foram seguidas durante o início da estação reprodutiva. O diâmetro, área e volume do Corpo Lúteo foram então obtidos através do modo B, bem como a sua vascularização através do modo Power Doppler.As análises da concentração plasmática de P4 foram feitas com recurso ao rádio-immuno-ensaio (RIA). No presente estudo, e contrariamente a estudos prévios, nenhuma relação foi encontrada entre o diâmetro, área e volume dos CL avaliados e a concentração de P4 circulante. Uma possível relação entre as áreas vasculares dos CL e dos píxeis obtidos nas imagens power Doppler foi visualmente avaliada. Porem nenhuma diferença na intensidade nos padrões vasculares foi observada, o que poderá indicar que não existe uma relação directa entre a concentração de P4 e a vascularização do CL.
ABSTRACT - The Doppler ultrasound is an emerging technology that has the potential to increase diagnostic capabilities of equine veterinarians. This technology is based on Doppler-shift frequencies, wherein the ultrasound frequency depends on the movements of red cells inside the vessels. Corpus luteum (CL) function is dependent on blood supply, which not only provides steroid precursors but also releases progesterone into the systemic circulation. A more sensitive Doppler technique, the Power Doppler mode, was applied to evaluate a possible relationship between CL characteristics and plasma progesterone (P4) concentration. For this purpose, nine (n=9) mares were followed during the early breeding season. Corpus luteum diameter, area, and volume were assessed with B-mode grey ultrasound and vascularisation was evaluated using power Doppler and plasma P4 determination was performed by radioimmunoassay (RIA). In this study, in disagreement with some previous reports, no relationship was found between the CL cross sectional diameters, areas and volumes with plasma P4 concentrations. The relationship between CL vascularised areas and pixels in the power Doppler images was visually assessed by two trained veterinarians. No colour intensity differences among samples was observed. Therefore, it is unlikely that a relationship between plasma P4 concentration and vascularisation exists in the equine CL.
13
Petroff, Brian Kelli. "Mechanisms of Hormone Action in the Porcine Corpus Luteum /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487934589976858.
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14
Sargent, Eva Lee. "The effects of intraluteal infusion of prostaglandin-synthesis inhibitors on the function of the primate corpus luteum." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184406.
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Exogenous prostaglandins (PGs) have been reported to suppress or to promote the function of the primate corpus luteum in vitro and in vivo, but the role of endogenous ovarian prostaglandins in regulating luteal function during the menstrual cycle is unknown. Infusion (via osmotic pump) of the prostaglandin-synthesis inhibitor sodium meclofenamate into the corpus luteum, but not via the jugular vein, during the midluteal phase of the menstrual cycle resulted in a decline in progesterone levels and premature menses in rhesus monkeys (Macaca mulatta). These results suggest that meclofenamate suppresses the production of an obligatory luteotropic prostaglandin or other metabolite of arachidonic acid. We were unable to confirm that ovarian prostaglandin synthesis was diminished during treatment, since we could not consistently measure a gradient in PGE or PGF₂(α) across the ovary. Dispersed cells from the macaque corpus luteum produced PGF₂(α) in vitro. Production was stimulated by exposure to arachidonic acid and was inhibited by meclofenamate and another prostaglandin-synthesis inhibitor, flurbiprofen. Although the two drugs were potent inhibitors of prostaglandin synthesis in vitro, intraluteal infusion of flurbiprofen in monkeys did not mimic the luteolytic effects of meclofenamate. These studies provide the first evidence of an obligatory luteotropic role for a metabolite of arachidonic acid during the primate luteal phase. However the data suggest that the luteolytic effect of meclofenamate in vivo is not mediated entirely by the inhibition of local prostaglandin synthesis. Further studies are needed to determine the mechanism(s) of meclofenamate-induced luteolysis and to identify the putative obligatory luteotropin.
15
Teschner, Dominik [Verfasser]. "Zur Charakterisierung sonographischer Befunde am Corpus haemorrhagicum und Corpus luteum der Stute / Dominik Teschner." Berlin : Freie Universität Berlin, 2008. http://d-nb.info/1023329271/34.
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16
Choudhary, Ekta. "Prostaglandin F₂[subscript alpha] (PGF₂[subscript alpha])--independent and--dependent regulation of the bovine luteal endothelin system." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4182.
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Thesis (M.S.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains viii, 40 p. : ill. Includes abstract. Includes bibliographical references (p. 36-40).
17
Jones, David Stephen Charnock. "Studies of oxytocin neurophysin mRNA in the ovine corpus luteum." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357761.
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18
De, Andrea Ribeiro Luciana <1971>. "Angiogenesis and angioregression gene expression analyses in swine corpus luteum." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/428/1/Tesi_dottorato_Luciana_de_Andrea_Ribeiro_-_XIX_ciclo.pdf.
Full textAbstract:
The corpus luteum (CL) lifespan is characterized by a rapid growth,
differentiation and controlled regression of the luteal tissue, accompanied by
an intense angiogenesis and angioregression. Indeed, the CL is one of the
most highly vascularised tissue in the body with a proliferation rate of the
endothelial cells 4- to 20-fold more intense than in some of the most
malignant human tumours. This angiogenic process should be rigorously
controlled to allow the repeated opportunities of fertilization. After a first
period of rapid growth, the tissue becomes stably organized and prepares
itself to switch to the phenotype required for its next apoptotic regression. In
pregnant swine, the lifespan of the CLs must be extended to support
embryonic and foetal development and vascularisation is necessary for the
maintenance of luteal function. Among the molecules involved in the
angiogenesis, Vascular Endothelial Growth Factor (VEGF) is the main
regulator, promoting endothelial cells proliferation, differentiation and survival
as well as vascular permeability and vessel lumen formation. During vascular
invasion and apoptosis process, the remodelling of the extracellular matrix is
essential for the correct evolution of the CL, particularly by the action of
specific class of proteolytic enzymes known as matrix metalloproteinases
(MMPs). Another important factor that plays a role in the processes of
angiogenesis and angioregression during the CL formation and luteolysis is the isopeptide Endothelin-1 (ET-1), which is well-known to be a potent
vasoconstrictor and mitogen for endothelial cells. The goal of the present
thesis was to study the role and regulation of vascularisation in an adult
vascular bed. For this purpose, using a precisely controlled in vivo model of
swine CL development and regression, we determined the levels of
expression of the members of VEGF system (VEGF total and specific
isoforms; VEGF receptor-1, VEGFR-1; VEGF receptor-2, VEGFR-2) and ET-
1 system (ET-1; endothelin converting enzyme-1, ECE-1; endothelin receptor
type A, ET-A) as well as the activity of the Ca++/Mg++-dependent
endonucleases and gelatinases (MMP-2 and MMP-9). Three experiments
were conducted to reach such objectives in CLs isolated from ovaries of
cyclic, pregnant or fasted gilts.
In the Experiment I, we evaluated the influence of acute fasting on VEGF
production and VEGF, VEGFR-2, ET-1, ECE-1 and ET-A mRNA expressions
in CLs collected on day 6 after ovulation (midluteal phase). The results
indicated a down-regulation of VEGF, VEGFR-2, ET-1 and ECE-1 mRNA
expression, although no change was observed for VEGF protein.
Furthermore, we observed that fasting stimulated steroidogenesis by luteal
cells. On the basis of the main effects of VEGF (stimulation of vessel growth
and endothelial permeability) and ET-1 (stimulation of endothelial cell
proliferation and vasoconstriction, as well as VEGF stimulation), we
concluded that feed restriction possibly inhibited luteal vessel development.
This could be, at least in part, compensated by a decrease of vasal tone due
to a diminution of ET-1, thus ensuring an adequate blood flow and the
production of steroids by the luteal cells.
In the Experiment II, we investigated the relationship between VEGF,
gelatinases and Ca++/Mg++-dependent endonucleases activities with the
functional CL stage throughout the oestrous cycle and at pregnancy. The
results demonstrated differential patterns of expression of those molecules in
correspondence to the different phases of the oestrous cycle. Immediately
after ovulation, VEGF mRNA/protein levels and MMP-9 activity are maximal.
On days 5–14 after ovulation, VEGF expression and MMP-2 and -9 activities
are at basal levels, while Ca++/Mg++-dependent endonuclease levels
increased significantly in relation to day 1. Only at luteolysis (day 17),
Ca++/Mg++-dependent endonuclease and MMP-2 spontaneous activity
increased significantly. At pregnancy, high levels of MMP-9 and VEGF were
observed. These results suggested that during the very early luteal phase,
high MMPs activities coupled with high VEGF levels drive the tissue to an
angiogenic phenotype, allowing CL growth under LH (Luteinising Hormone)
stimulus, while during the late luteal phase, low VEGF and elevate MMPs
levels may play a role in the apoptotic tissue and extracellular matrix
remodelling during structural luteolysis.
In the Experiment III, we described the expression patterns of all distinct
VEGF isoforms throughout the oestrous cycle. Furthermore, the mRNA expression and protein levels of both VEGF receptors were also evaluated.
Four novel VEGF isoforms (VEGF144, VEGF147, VEGF182, and
VEGF164b) were found for the first time in swine and the seven identified
isoforms presented four different patterns of expression. All isoforms showed
their highest mRNA levels in newly formed CLs (day 1), followed by a
decrease during mid-late luteal phase (days 10–17), except for VEGF182,
VEGF188 and VEGF144 that showed a differential regulation during late
luteal phase (day 14) or at luteolysis (day 17). VEGF protein levels paralleled
the most expressed and secreted VEGF120 and VEGF164 isoforms. The
VEGF receptors mRNAs showed a different pattern of expression in relation
to their ligands, increasing between day 1 and 3 and gradually decreasing
during the mid-late luteal phase. The differential regulation of some VEGF
isoforms principally during the late luteal phase and luteolysis suggested a
specific role of VEGF during tissue remodelling process that occurs either for
CL maintenance in case of pregnancy or for noncapillary vessel development
essential for tissue removal during structural luteolysis.
In summary, our findings allow us to determine relationships among factors
involved in the angiogenesis and angioregression mechanisms that take
place during the formation and regression of the CL. Thus, CL provides a
very interesting model for studying such factors in different fields of the basic
research.
19
De, Andrea Ribeiro Luciana <1971>. "Angiogenesis and angioregression gene expression analyses in swine corpus luteum." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/428/.
Full textAbstract:
The corpus luteum (CL) lifespan is characterized by a rapid growth,
differentiation and controlled regression of the luteal tissue, accompanied by
an intense angiogenesis and angioregression. Indeed, the CL is one of the
most highly vascularised tissue in the body with a proliferation rate of the
endothelial cells 4- to 20-fold more intense than in some of the most
malignant human tumours. This angiogenic process should be rigorously
controlled to allow the repeated opportunities of fertilization. After a first
period of rapid growth, the tissue becomes stably organized and prepares
itself to switch to the phenotype required for its next apoptotic regression. In
pregnant swine, the lifespan of the CLs must be extended to support
embryonic and foetal development and vascularisation is necessary for the
maintenance of luteal function. Among the molecules involved in the
angiogenesis, Vascular Endothelial Growth Factor (VEGF) is the main
regulator, promoting endothelial cells proliferation, differentiation and survival
as well as vascular permeability and vessel lumen formation. During vascular
invasion and apoptosis process, the remodelling of the extracellular matrix is
essential for the correct evolution of the CL, particularly by the action of
specific class of proteolytic enzymes known as matrix metalloproteinases
(MMPs). Another important factor that plays a role in the processes of
angiogenesis and angioregression during the CL formation and luteolysis is the isopeptide Endothelin-1 (ET-1), which is well-known to be a potent
vasoconstrictor and mitogen for endothelial cells. The goal of the present
thesis was to study the role and regulation of vascularisation in an adult
vascular bed. For this purpose, using a precisely controlled in vivo model of
swine CL development and regression, we determined the levels of
expression of the members of VEGF system (VEGF total and specific
isoforms; VEGF receptor-1, VEGFR-1; VEGF receptor-2, VEGFR-2) and ET-
1 system (ET-1; endothelin converting enzyme-1, ECE-1; endothelin receptor
type A, ET-A) as well as the activity of the Ca++/Mg++-dependent
endonucleases and gelatinases (MMP-2 and MMP-9). Three experiments
were conducted to reach such objectives in CLs isolated from ovaries of
cyclic, pregnant or fasted gilts.
In the Experiment I, we evaluated the influence of acute fasting on VEGF
production and VEGF, VEGFR-2, ET-1, ECE-1 and ET-A mRNA expressions
in CLs collected on day 6 after ovulation (midluteal phase). The results
indicated a down-regulation of VEGF, VEGFR-2, ET-1 and ECE-1 mRNA
expression, although no change was observed for VEGF protein.
Furthermore, we observed that fasting stimulated steroidogenesis by luteal
cells. On the basis of the main effects of VEGF (stimulation of vessel growth
and endothelial permeability) and ET-1 (stimulation of endothelial cell
proliferation and vasoconstriction, as well as VEGF stimulation), we
concluded that feed restriction possibly inhibited luteal vessel development.
This could be, at least in part, compensated by a decrease of vasal tone due
to a diminution of ET-1, thus ensuring an adequate blood flow and the
production of steroids by the luteal cells.
In the Experiment II, we investigated the relationship between VEGF,
gelatinases and Ca++/Mg++-dependent endonucleases activities with the
functional CL stage throughout the oestrous cycle and at pregnancy. The
results demonstrated differential patterns of expression of those molecules in
correspondence to the different phases of the oestrous cycle. Immediately
after ovulation, VEGF mRNA/protein levels and MMP-9 activity are maximal.
On days 5–14 after ovulation, VEGF expression and MMP-2 and -9 activities
are at basal levels, while Ca++/Mg++-dependent endonuclease levels
increased significantly in relation to day 1. Only at luteolysis (day 17),
Ca++/Mg++-dependent endonuclease and MMP-2 spontaneous activity
increased significantly. At pregnancy, high levels of MMP-9 and VEGF were
observed. These results suggested that during the very early luteal phase,
high MMPs activities coupled with high VEGF levels drive the tissue to an
angiogenic phenotype, allowing CL growth under LH (Luteinising Hormone)
stimulus, while during the late luteal phase, low VEGF and elevate MMPs
levels may play a role in the apoptotic tissue and extracellular matrix
remodelling during structural luteolysis.
In the Experiment III, we described the expression patterns of all distinct
VEGF isoforms throughout the oestrous cycle. Furthermore, the mRNA expression and protein levels of both VEGF receptors were also evaluated.
Four novel VEGF isoforms (VEGF144, VEGF147, VEGF182, and
VEGF164b) were found for the first time in swine and the seven identified
isoforms presented four different patterns of expression. All isoforms showed
their highest mRNA levels in newly formed CLs (day 1), followed by a
decrease during mid-late luteal phase (days 10–17), except for VEGF182,
VEGF188 and VEGF144 that showed a differential regulation during late
luteal phase (day 14) or at luteolysis (day 17). VEGF protein levels paralleled
the most expressed and secreted VEGF120 and VEGF164 isoforms. The
VEGF receptors mRNAs showed a different pattern of expression in relation
to their ligands, increasing between day 1 and 3 and gradually decreasing
during the mid-late luteal phase. The differential regulation of some VEGF
isoforms principally during the late luteal phase and luteolysis suggested a
specific role of VEGF during tissue remodelling process that occurs either for
CL maintenance in case of pregnancy or for noncapillary vessel development
essential for tissue removal during structural luteolysis.
In summary, our findings allow us to determine relationships among factors
involved in the angiogenesis and angioregression mechanisms that take
place during the formation and regression of the CL. Thus, CL provides a
very interesting model for studying such factors in different fields of the basic
research.
20
Wegner, Julie Anne. "The interaction of cytosolic-free calcium in PGF(2alpha)-induced luteal regression in ovine corpus luteum." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185210.
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The corpus luteum is an endocrine gland which forms in the ovary each reproductive cycle, secretes progesterone, and regresses if pregnancy does not occur. An understanding of the factors and mechanisms that determine the function and lifespan of the corpus luteum is fundamental to the understanding of the mechanisms that cause luteal dysfunction. Prostaglandin F₂(α)(PGF₂(α)) is the primary lutelytic agent in ewes and appears to initiate luteal regression by altering cytosolic-free calcium ([Ca²⁺]ᵢ) and stimulating calcium-dependent intracellular pathways. The primary focus of this dissertation was to investigate the roles of PGF₂(α) and calcium in the regulation of progesterone secretion in the ovine corpus luteum. In fura-2 loaded large cells, PGF₂(α) (0.5 μM) induced a rapid transient increase in [Ca²⁺]ᵢ followed by a sustained elevation of [Ca²⁺]ᵢ. The transient nature of the [Ca²⁺]ᵢ increase was due, at least in part, to the ability of PGF₂(α) to stimulate (p < 0.05)⁴⁵Ca²⁺ efflux. PGF₂(α) did not alter [Ca²⁺]ᵢ in small cells. The PGF₂(α)-induced calcium transient was modified by incubation of large cells in conditions known to alter calcium homeostasis. The transient was attenuated by incubation of large cells in Ca²⁺-free medium (±EGTA). These results suggest that PGF₂(α) induces release of calcium from intracellular calcium pools. However, pre-incubation (2 min) of large cells with 1mM LaCl₃ eliminated the PGF₂(α)-induced calcium transient, suggesting a role of extracellular calcium. Two different results were observed in this study regarding the role of calcium in the regulation of progesterone secretion. First, the inhibitory effect of PGF₂(α) on secretion of progesterone was reduced under conditions that reduced the magnitude of the PGF₂(α)-induced calcium transient. Second, a sustained elevation or reduction in [Ca²⁺]ᵢ level also reduced basal progesterone secretion in large cells. Thus, both phases of the PGF₂(α)-induced [Ca²⁺]ᵢ response, transient increase and sustained elevation, appear to be linked to the inhibitory action of PGF₂(α) on progesterone secretion. Finally, this study provides evidence to suggest that large and small cells differ in their ability to regulate calcium homeostasis.
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Oliveira, Cleber Barbosa de. "Avaliação das células luteais de fêmeas taurinas (Bos taurus taurus) e zebuínas (Bos taurus indicus) /." Jaboticabal : [s.n.], 2007. http://hdl.handle.net/11449/105940.
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Orientador: César Roberto EsperBanca: José Domingos Guimarães
Banca: José Octávio Jacomini
Banca: Paulo Henrique Franceschini
Banca: Francisco Guilherme Leite
Resumo: O objetivo deste trabalho foi determinar o número de células luteais bovinas, comparando fêmeas taurinas com zebuínas no início e final do ciclo estral. Foram coletados corpos lúteos de 16 fêmeas sendo 8 taurinas e 8 zebuínas, distribuídas em 4 grupos sendo coletados os ovários nos dias 3 a 5 (2 grupos: taurino e zebuíno) e 16 a 18 (2 grupos: taurino e zebuíno) do ciclo estral. Os corpos lúteos foram processados para microscopia óptica e avaliouse as células luteais pequenas, grandes e intermediárias, quanto ao número celular, diâmetro, área e perímetro. Os animais taurinos apresentaram maior quantidade de células luteais pequenas que os zebuínos no início do ciclo estral (p
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Doerr, Matthew D. "The role of the endothelin system in prostaglandin F₂[alpha]-induced luteolysis." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5202.
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Thesis (M.S.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; containsvi, 64 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 51-64).
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Southee, J. A. "Luteal function after induced ovulation in the sheep." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376415.
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Bolden-Tiller, Olga U. "Characterization of progesterone receptor in bovine corpora lutea /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3074376.
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Ochoa, Julián Camilo [UNESP]. "Expressão gênica do corpo lúteo após pulsos intrauterinos com doses baixas de prostaglandina E1 e F-2 alfa em vacas." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/144324.
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Em ruminantes a luteólise natural é caraterizada pela liberação de vários pulsos de prostaglandina F2alfa (PGF) produzidos pelo útero. A PGF é o hormônio luteolítico, enquanto a prostaglandina E1 (PGE1) é considerada um mediador luteoprotetor. Em estudos anteriores, infusões com doses baixas de PGF no útero com intervalos de 6 horas (h) resultou em regressão do corpo luteo (CL). A proposta deste experimento é desenvolver um modelo para avaliar o efeito de baixas doses de PGE1, também infundidas no lúmen uterino sobre a resposta luteal à PGF intrauterina (IU). Vacas no dia 10 do ciclo estral receberam infusões IU de salina (0,1 ml de salina + 0,1 ml de DMSO), PGE (2 mg de PGE1 em 0,1ml de DMSO) ou PGF (0,25 mg of PGF em 0,1 ml de salina) em intervalos de 6 h em um desenho experimental 2 X 2. Portanto os animais foram agrupados em quatro tratamentos: SALINA (4 infusões de salina; n=5), PGE (4 infusões de PGE1; n=5), PGF (4 infusões de PGF; n=5) e PGE+PGF (4 infusões de PGE1+PGF; n=5). As concentrações plasmáticas de progesterona (P4) foram dosadas por radioimunoensaio e o volume luteal foi determinado por ultrassonografia transretal. As concentrações circulantes de PGFM e PGEM foram dosadas antes e 10 minutos após as primeiras duas infusões. Biopsias luteais foram coletadas de cada vaca 30 minutos após cada infusão para determiner a expressão de genes em resposta a cada tratamento. As concentrações circulantes de PGFM 10 minutos após as infusões foram maiores em vacas que receberam tratamentos com PGF e PGE+PGF em comparação com as vacas tratadas com salina e PGE. Da mesma forma, as concentrações de PGEM 10 minutos após cada infusão foram maiores em vacas tratadas com PGE e PGE+PGF em comparação com vacas dos grupos salina e PGF. As concentrações de P4 diminuiram no grupo PGF em comparação com o grupo Salina no tempo 12-h (48,9% do controle) após a primeira infusão de PGF, no tempo 24-h (20,2% do controle), e em todos tempos subsequentes (P < 0,05). Não foram encontradas diferenças nas concentrações circulantes de P4 entre os grupos Salina, PGE e PGF+PGE. Houve também uma diminuição do volume luteal entre o grupo PGF e os outros três grupos que foi observada nos tempos 24-h (56,4% do controle), 48-h (30,6% do controle), e 72-h (20,4% do controle) após o tratamento com PGF (P<0.05). Não houve diferenças no volume luteal entre os tratamentos salina, PGE e PGE+PGF. Por tanto, infusões IU simultâneas de baixas doses de PGE1 bloquearam a ação luteolitica de pulsos IU de PGF em vacas, como observado nas mudanças circulantes de P4 e volume luteal. Análises da expressão génica nas biopsias luteais coletadas após o terceiro pulso de PGF, indicam o padrão tipico de expressão de genes em resposta ao tratamento com PGF (FGF2, EGR1, FOS e FAS aumentaram; PTGFR, VEGFA, NR5A1 e STAR diminuiram) e o tratamento PGE+PGF bloqueou completamente as mudanças na expressão destes genes. Infusões IU de PGF e PGE1 parecem ser um excelente modelo para determiner o padrão de expressão de genes envolvidos no efeito luteoprotetor da PGE1.
In ruminants, natural luteolysis is characterized by the release of several pulses of prostaglandin F2alpha (PGF) produced by the uterus. Prostaglandin F2alpha is the luteolytic hormone, whereas prostaglandin E1 (PGE1) is considered to be a luteoprotective mediator. In previous studies, low doses of PGF infused into the uterus at 6 hour (h) intervals resulted in regression of the corpus luteum (CL). This study was designed to develop a model to study the effect of low doses of PGE1, also infused into the uterine lumen, on the luteal responses to intrauterine (IU) PGF. Cows on day 10 of the estrous cycle received IU infusions of saline (0,1 ml of saline + 0,1 ml of DMSO), PGE (2 mg of PGE1 in 0,1ml of DMSO) or PGF (0,25 mg of PGF in 0,1 ml of saline) at 6-h intervals in a 2 X 2 experimental design. Thus, there were four treatment groups: SALINE (4 saline infusions; n=5), PGE (4 PGE1 infusions; n=5), PGF (4 PGF infusions; n=5), and PGE+PGF (4 PGE1+PGF infusions; n=5). Radioimmunoassay was used to measure circulating progesterone (P4) concentrations and luteal volume was determined by transrectal ultrasonography. Circulating concentrations of PGFM and PGEM were measured before and 10 minutes after the first two infusions. A luteal biopsy was collected from each cow at 30 minutes after each infusion for later determination of gene expression in response to each treatment. Circulating concentrations of PGFM 10 minutes after infusions were greater in cows receiving treatments with PGF and PGE+PGF than in Saline or PGE-treated cows. In the same way, concentrations of PGEM 10 minutes after infusions, were greater in cows that were treated with PGE and PGE+PGF than in saline and PGF-treated cows. Concentrations of P4 in the PGF group decreased compared to those in the saline group by 12-h (48.9% of control) after first infusion of PGF, at 24-h (20,2% of control), and all subsequent time points (P < 0,05). No differences in circulating P4 concentrations were found between Saline, PGE, and PGF+PGE. There was also a decrease of luteal volume between the PGF group and the other three groups that was detectable at 24 (56,4% of control), 48 (30,6% of control), and 72 (20,4% of control) h after PGF treatment (P<0.05). There were no differences in luteal volume between Saline, PGE, or PGE+PGF. Thus, simultaneous IU infusion of a low dose of PGE1 blocked the luteolytic actions of IU PGF pulses in cattle, as measured by changes in circulating P4 and luteal volume. Analyses of gene expression in the luteal biopsy taken after the third PGF pulse indicate a typical pattern of gene expression in response to the PGF treatments (FGF2, EGR1, FOS and FAS increased; PTGFR, VEGFA, NR5A1 and STAR decreased) and that simultaneous PGE1 treatment completely blocked these gene expression changes. Thus, IU infusion of PGF and PGE1 seems to provide an excellent model for determining the patterns of gene expression involved in the luteoprotective effect of PGE1.
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Abdo, Michael A. "Tumour necrosis factor : alpha signal transduction in rat corpus luteum apoptosis." University of Western Australia. School of Anatomy and Human Biology, 2002. http://theses.library.uwa.edu.au/adt-WU2003.0024.
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[Formulae and special characters can only be approximated here. Please see the pdf version of the abstract for an accurate reproduction.] Apoptosis is a morphologically distinct form of cell death that is involved in the regulation of normal and aberrant cell systems. The complexities of the apoptotic cell death pathway arise from variation in both the cellular specialisation and initial stimulus. The corpus luteum (CL) is an endocrine gland that whilst critical to the maintenance of pregnancy in the rat, regresses at the completion of each oestrous cycle and pregnancy. This regression is facilitated through apoptosis; though, the stimulus and factors involved in the apoptotic pathway are poorly understood. Previous studies suggest that CL regression is not initiated through failure of luteotrophic support, but rather the active production of a luteolytic factor, of which tumour necrosis factor -alpha (TNFα) is one possible candidate. Several publications have reported the participation of the immune system in ovarian events. There is evidence that TNFα expression within the ovary is coordinated between cells of the immune system and the hormonal regulation of the CL. This study has focussed on the role of TNFα in CL apoptosis and the factors involved in this apoptotic pathway. TNFα-induced cell death is governed by the presence of the two TNFα receptors (TNFR) and several second messenger systems that include; the sphingolipids, mitogen-activated protein (MAP) kinases, nitric oxide (NO), nuclear factor-kappaB (NF-κB) and the caspases. These factors and their interactions were assessed in the rat CL during pregnancy and post-partum, and in vitro. Apoptosis was measured through the analysis of DNA fragmentation using DNA 3’ end labelling and single cell electrophoresis (COMET assay). Assessment of mRNA and protein expression was through Real-time RT-PCR and Western blot analysis; proteins were localised within the CL by immunocytochemistry. In addition, specific measurement of sphingolipid expression and nitric oxide (NO) production was by high performance liquid chromatography (HPLC) and NO assay respectively. Following parturition, TNFα mRNA and protein expression increased corresponding to the onset of CL apoptosis and increased expression of the chemotactic factor monocyte chemoattractant protein -1 (MCP-1). Furthermore, CL apoptosis was induced by treatment with recombinant TNFα in a time- and dose-dependent manner. A similar effect was observed in isolated luteal cells. Simultaneously, the functional regression of the CL was assessed by measurement of both progesterone synthesis and steroidogenic acute regulatory (StAR) protein expression. StAR mRNA and protein expression declined toward parturition in vivo. Immunocytochemical studies revealed the presence of TNFα receptors 1 (TNFR1) and 2 (TNFR2) in luteal cells. Furthermore, TNFR mRNA was isolated from CL throughout pregnancy and post-partum. Subsequently, the role of the sphingolipids ceramide and sphingosine was examined during CL apoptosis in vitro. Ceramide and sphingosine were found to be potent apoptotic agents when administered in vitro (50µM). The downstream signal transduction of TNFα and ceramide was assessed through MAP kinase expression. Both TNFα and ceramide increased expression of the pro-apoptotic p38 MAP kinase with no change to the non-apoptotic extracellular signal-related kinase (ERK1&2). Despite previous reports of c-Jun NH2 terminal kinase (JNK) involvement in the cell death pathway, JNK expression was not evident in the rat CL. The caspases are a family of cysteine proteases central to the regulation and execution of apoptosis. General inhibition of the caspase cascade in vitro was effective in preventing apoptosis regardless of the apoptotic stimulus (TNFα, ceramide and sphingosine), suggesting that this pathway is central to CL apoptosis. Specific inhibition of several caspases produced a varying effect; inhibition of caspases 3, 6 and 8 significantly reduced the level of TNFα-induced apoptosis, thus supporting their classification as either regulatory or effector caspases. NO is endowed with the unique ability to initiate and to block apoptosis and this dichotomy extends to the cytotoxic actions of TNFα. Inhibition of NO production by treating CL with L-NAME prevented the onset of apoptosis, whilst NO production increased in response to increasing levels of apoptosis following trophic withdrawal. However, this effect was not seen during TNFα-induced apoptosis, suggesting that the actions of NO are independent of TNFα. The data presented within this study examine multiple elements of the TNFα cell death pathway in a single system. The results suggest that these elements are involved in TNFα signal transduction and furthermore, in rat CL apoptosis. It can be said that TNFα plays an active role in CL regression through the activation of the caspases, the sphingolipids and the MAP kinases.
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Brockhan-Lüdemann, Maren [Verfasser]. "Farbdopplersonographische Untersuchungen zur Funktion des bovinen Corpus luteum / Maren Brockhan-Lüdemann." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2010. http://d-nb.info/1000021076/34.
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Strüve, Klaas-Dietrich [Verfasser]. "Einfluss von Entzündungen auf das bovine Corpus luteum / Klaas-Dietrich Strüve." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2013. http://d-nb.info/1037883829/34.
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Rusbridge, Sheila Margaret. "Characterization of the GnRH-induced corpus luteum in the cycling heifer." Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/29977.
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Although recent studies in other laboratories have greatly increased our understanding of luteal function in cattle, we are still unable to accurately synchronise luteolysis, preovulatory follicular growth and ovulation with commercially available pharmacological preparations. The aim of these studies was to investigate the factor(s) which controls the formation, function and regression of the GnRH-induced corpus luteum (CL). Initially, we sought to develop an experimental model to examine the characteristics of the CL induced in intact heifers with normal oestrous cyclicity, by GnRH injection in the early luteal phase. Administration of GnRH on Day 6 after the synchronised oestrus resulted in ovulation and formation of an additional CL in >70% of animals. Following prostaglandin F2α(PGF2α) in the mid-luteal phase, the spontaneously-formed CL underwent luteolysis while the induced CL did not, leading to a delay in return to oestrus associated with a persistence of luteal function. Having demonstrated the ovulatory competence of the dominant follicle of the first follicular wave, and the formation of a functional CL, it was of interest to examine the reason for the premature demise of the induced CL in the GnRH responders when compared to the spontaneously-formed CL. Administration of steroid-stripped bovine follicular fluid (bFF), which suppressed the growth of the dominant follicle, and reduced serum oestradiol concentrations, resulted in a further delay in the return to oestrus and a significant extension in the lifespan of the induced CL, when compared to the untreated responders, and provided circumstantial evidence that oestradiol was the endogenous agent responsible for regression of the induced CL.
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Dickson, Sarah. "The control and manipulation of angiogenesis in the primate corpus luteum." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/23326.
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In the marmoset luteal angiogenesis was manipulated by the administration of various putative angiogenesis inhibitors specifically targeting early luteal intense angiogenesis and mid-luteal ongoing angiogenesis. Luteal function was assessed by measuring plasma progesterone. Firstly, the effects of the angiogenesis inhibitor, TNP-470, shown to inhibit pregnancy in the mouse, were examined. This failed to affect endothelial cell proliferation or development of the microvasculature, which was confirmed by normal plasma progesterone concentrations, emphasising the need for caution in extrapolating results from the rodent. Secondly, in two studies marmosets were treated with a GnRH antagonist to analyse the control of luteal angiogenesis by the major luteotropic factor, LH in the early and mid-luteal phases. Withdrawal of LH had a devastating effect on the high level of endothelial cell proliferation in the early luteal phase but did not disturb the ongoing mid-luteal phase angiogenesis. Lutein cell morphology was severely disrupted after treatment at both stages, preventing the production and secretion of progesterone. Finally VEGF was immunoneutralised in three separate regimes of treatment in the early, from early to mid-, and specifically in the mid-luteal phase. Treatment suppressed proliferation in the early lateral phase and subsequently prevented formation of the mid-luteal microvascular network. The ongoing angiogenesis of the mid-CL was shown to be VEGF dependent, and VEGF withdrawal affected pericyte recruitment at all stages. To explore the endogenous control of luteal angiogenesis, expression of the angioproteins and their receptor, Tie 2 were analysed in association with expression of VEGF and its receptors in the human, using quantitative RT-PCR. The early luteal phase was associated with peak expression of all factors with slight increases in mRNAs for Ang-2 in the late CL and VEGF in the rescued. Since physiological angiogenesis occurs exclusively in reproductive tissues in the healthy adult, manipulation of angiogenesis may have important clinical implications in the treatment of infertility, in which angiogenesis is lacking, or for the development of anew approach to post-ovulatory fertility control based upon suppression of angiogenesis.
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Woad, Kathryn Jane. "The insulin-like growth factor system in the bovine corpus luteum." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/23270.
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Bovine CL were collected on days 5, 10, and 15 of the oestrous cycle following synchronised oestrus. In addition, CL were collected following prostaglandin-induced luteolysis. In situ hybridisation detected luteal expression of IGF-I, -II and the type 1 IGF receptor mRNA throughout the oestrous cycle. IGF-I mRNA concentrations varied significantly during the cycle, increasing from low levels in the early luteal phase (day 5) to high levels in the late luteal phase (day 15). Concentrations were maximal 48 hours after exogenous prostaglandin. In contrast, there was no significant effect of day of the oestrous cycle on IGF-II and the type 1 IGF receptor mRNA concentrations in the corpus luteum. IGF-II mRNA expression was localised to a subset of steroidogenic luteal cells and was also associated with cells of the luteal vasculature. In addition, the relative abundance of IGF-II mRNA was greater than that of IGF-I mRNA. mRNA encoding the type 1 IGF receptor was widely expressed, in a pattern suggestive of large and small luteal cell expression. The actions of the IGFs are modulated by their association with members of a family of IGF-specific binding proteins (IGFBPs), which regulate the transport of IGFs and their presentation to specific receptors. In situ hybridisation detected mRNA encoding IGFBP-2, -3, and -4 in the bovine corpus luteum throughout the luteal phase. IGFBP-2 and -4 mRNA concentrations were low within the corpus luteum, and showed no temporal variation. In addition, a subset of large vessels in the periphery of the CL showed moderate to intense hybridisation for IGFBP-2 mRNA. IGFBP-3 mRNA concentrations were high throughout the luteal phase, and expression was localised to small luteal cells and cells of the luteal vasculature. These data demonstrate for the first time that the bovine CL is a site of IGF production, reception and regulation, and further support the hypothesis that the IGF system is important in regulating luteal function in the cow.
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Tarso, Gusmão da Silva Saulo De. "HEMODYNAMICS STUDIES OF THE PREOVULATORY FOLLICLE AND CORPUS LUTEUM IN CATTLE." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/dissertations/1104.
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Productivity efficiency in the livestock sector depends upon reproduction success at the farms. Evaluation of follicle and corpus luteum hemodynamics by color-Doppler ultrasonography is becoming more commonly used in cattle reproductive management. Improved understanding of the relationships between size and blood flow of the preovulatory follicle (POF) and corpus luteum (CL) with the subsequent systemic progesterone production, and the impact of those factors on fertility, would provide information to help maximize fertility in cattle reproduction. Three studies were conducted in this dissertation with the following general objectives: I) evaluate the relationships between follicle and corpus luteum dimensions and blood flow, and the influence of follicle size and wall blood flow on systemic progesterone production by the subsequent CL; II) study the relationships between follicle wall blood flow within different follicle size categories, between cows and heifers, and the effect on pregnancy rates; and III) develop a novel and reliable objective method for evaluation of follicle wall blood flow. In study one, high positive correlations were found among all POF and CL end points, and progesterone concentrations. Ratios of POF, CL, and progesterone end points ranged from moderate to strong positive correlations. Linear regression dispersions among selected POF and CL end points and progesterone concentrations showed high significance when using POF dimensions to estimate CL dimensions as well as POF blood flow to estimate CL size and blood flow, and plasma progesterone concentrations. In study two, cows had larger and more vascularized follicles than heifers. Pregnant cows had larger follicles and tended to have more vascularized follicles than non-pregnant cows. Follicle blood flow was greater in the large follicle category compared with the small follicles, and tended to be greater than medium-size follicles. Moderate to strong correlations were found between follicle blood flow and small, medium, and large follicles. Pregnancy rates were similar among follicle diameter categories. In study three, a novel objective method (wall under flow, WUF) for evaluation of follicle wall blood flow using color-Doppler ultrasonography was tested. Results indicated that due to differences in follicle morphology and in area and location of the blood flow, the objective pixel analysis previously reported in the literature for evaluation of CL blood flow cannot be translated as a gold standard test to objectively evaluate blood flow in follicles. The WUF was a superior method to evaluate follicle wall blood flow when compared with other methods. Furthermore, pixel area method did not sustain the validation of subjective evaluations of follicle wall blood flow. In conclusion, this work demonstrated novel linear relationships among POF and CL end points which can be used to estimate the subsequent progesterone production by the CL. Additionally, POF wall blood flow was closely associated with an increase in follicle diameter; smaller follicles had lower blood flow when compared with larger follicles. Moreover, the WUF was a more reliable method to objectively evaluate follicle wall blood flow in cows than the pixel area method.
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Ceddia, Ryan P. "Sodium dependent vitamin C transporters in the sheep corpus luteum sequence analysis /." Connect to this title online, 2005. http://hdl.handle.net/1811/351.
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Thesis (Honors)--Ohio State University, 2005.Title from first page of PDF file. Document formattted into pages: contains, 28 p.; also includes graphics. Includes bibliographical references (p. 22-28). Available online via Ohio State University's Knowledge Bank.
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Bisplinghoff, Petra. "Angiogenese, Anti-Angiogenese und vaskuläre Regression am Modell des bovinen Corpus luteum." Berlin : Mensch-und-Buch-Verl, 2006. http://www.diss.fu-berlin.de/2006/494/index.html.
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Frankel, Sara. "The role of transforming growth factor-alpha in the human corpus luteum." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295876.
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Paice, Shannon. "Investigations of sodium dependent vitamin c transporters in the ovine corpus luteum." Connect to resource, 2008. http://hdl.handle.net/1811/35995.
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Starbuck, Melanie J. "Factors affecting reproductive efficiency of cattle." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4301.
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Thesis (Ph. D.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains ix, 150 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 116-149).
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Xu, Jing. "Luteinizing hormone-regulated genes and corticotropin releasing hormone/urocortin-receptor-binding protein system in the primate corpus luteum during the menstrual cycle : a dissertation /." Restricted access until December 2006 at:, 2006. http://content.ohsu.edu/u?/etd,148.
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Mankey, Julie E. "Effects of the oxytocin receptor blocker, atosiban, on function of ovine corpora lutea and responses to prostaglandin F₂ alpha." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10545.
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Thesis (M.S.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains viii, 61 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 39-52).
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Costine, Beth Alyson. "Evidence for a systemic embryotoxic effect of early luteal regression in the ewe." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1733.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains viii, 58 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 42-56).
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Costine, Beth Alyson. "Mechanisms of reduced luteal sensitivity to PGF₂[alpha] in ruminants." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3737.
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Thesis (Ph. D.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains xiii, 119 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 95-118).
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Oliveira, Cleber Barbosa de [UNESP]. "Avaliação das células luteais de fêmeas taurinas (Bos taurus taurus) e zebuínas (Bos taurus indicus)." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/105940.
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O objetivo deste trabalho foi determinar o número de células luteais bovinas, comparando fêmeas taurinas com zebuínas no início e final do ciclo estral. Foram coletados corpos lúteos de 16 fêmeas sendo 8 taurinas e 8 zebuínas, distribuídas em 4 grupos sendo coletados os ovários nos dias 3 a 5 (2 grupos: taurino e zebuíno) e 16 a 18 (2 grupos: taurino e zebuíno) do ciclo estral. Os corpos lúteos foram processados para microscopia óptica e avaliouse as células luteais pequenas, grandes e intermediárias, quanto ao número celular, diâmetro, área e perímetro. Os animais taurinos apresentaram maior quantidade de células luteais pequenas que os zebuínos no início do ciclo estral (p
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Dziallas, Deniz [Verfasser]. "Regulation of bovine corpus luteum expressed galectins and their immunoregulatory potential / Deniz Dziallas." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2011. http://d-nb.info/1013284070/34.
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Käßmeyer, Sabine. "Gefäßbildung des bovinen Corpus luteum in vitro Charakterisierung von Endothelzellen und endothelialen Progenitorzellen /." Berlin : Mensch-und-Buch-Verl, 2006. http://www.diss.fu-berlin.de/2006/231/index.html.
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Anderson, Lesley A. "The role of the immune system in regression of the bovine corpus luteum." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/29760.
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The aim of this study was to quantify immune cell populations within the cow corpus luteum (CL) throughout the oestrous cycle in order to investigate whether these cells could be involved in controlling luteal function, particularly around the time of luteolysis. Six CL were collected from each of four stages of the oestrous cycle and were identified on the basis of their gross appearance, for preliminary immunohistochemical studies. Immune cell populations and MHCII expression varied throughout the oestrous cycle. In particular, the number of macrophages, T-lymphocytes (CD5+, CD4+) and MHCII expression was significantly higher in late stage CL (after luteolysis) compared to all other stages. To study in more detail the cellular events associated with luteolysis, the oestrous cycles of 19 cows were synchronised. CL were collected between days 16 and 20 of the following oestrous cycle. A significant increase in the number of T-lymphocytes (CD5+, CD8+) was detected in CL collected from day 16 onwards, compared to days 13-14. This increase occurred prior to functional luteolysis. Artificially-induced luteolysis was then assessed as a potential model for further studies around luteolysis. CL collected 6, 12, and 24 hours after luteolysis induced using a single injection of 25mg PGF2α had undergone dramatic structural regression which bore little resemblance to events during normal luteolysis and so this model was rejected. The role of endogeoous PGF2α in inducing the influx of T-lymphocytes was then investigated. Production of PGF2α was inhibited in 12 cows between days 15 and 18 of the oestrous cycle and artificially replaced in six of the cows for 24 hours before collection of the CL on day 18. The number of macrophages was significantly lower in all animals in which PGF2α was inhibited compared to control animals but T-lymphocyte numbers were not significantly altered.
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Al-Ziʾabi, Omar. "A histological study of angiogenesis and cell death in the equine corpus luteum." Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/29737.
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Angiogenesis is a dynamic process of endothelial cell proliferation and microvessel formation regulated by the production of angiogenic factors, especially VEGF. It was established that the early luteal phase was associated with intense endothelial cell proliferation, expression of VEGF and the growth of the microvascular network. Angiogenesis continued during the mid-luteal phase by at a reduced level. However, VEGF remained high and the full microvasculature had been established for optimal progesterone secretion. During regression, endothelial cell proliferation and VEGF expression declined, with a reduction in vascularity and a marked progesterone decline. The combination of TUNEL immunostaining and ultrastructural examination provided definitive identification of the types of cell death involved in the CL. It was demonstrated that apoptotic and non-apoptotic mechanisms were involved in the demise of the CL. The presence of fragmented chromatin, pyknotic cells, round dense bodies and phagocytosis were considered as apoptotic features. Other changes (crenation of the nuclear membrane with shrinkage of the nucleus) seen in some luteal cells indicated there is an additional non-apoptotic form of cell death at luteolysis. TNFa, NO and bFGF immunostaining in the luteal cells during the luteal phase may indicate a paracrine and/or autocrine role for these factors in the CL and may play a role in luteal development and regression. This thesis has described for the first time the cellular changes of angiogenesis and regression post PGF2α-induced regression. The findings revealed massive neutrophils and vasodilation as well as a similar pattern of other cellular changes to those undergone during natural luteolysis. This study increases our understanding of equine CL control. It demonstrates that luteal angiogenesis is important for luteal function and it is likely that VEGF is essential for luteal angiogenesis. Luteolysis and cell death play a crucial role in ovarian cyclicity and the demise of luteal tissue represents both apoptotic and non-apoptotic pathways.
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Townson, David Harrison. "Mechanisms of regulation of prostaglandin synthesis by cytokines in the bovine corpus luteum /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487846885779872.
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Duncan, William Colin. "The human corpus luteum : functional and structural effects of maternal recognition of pregnancy." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/21218.
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This thesis aimed to investigate luteolysis, and the functional and structural effects of maternal recognition of pregnancy in the primate corpus luteum. As progesterone production by the corpus luteum is dependent on luteinising hormone (LH) from the anterior pituitary gland, the expression and localisation of the LH/hCG receptor, key elements of the steroidogenic pathway and the progesterone receptor were studied. In addition, as the corpus luteum undergoes extensive tissue remodelling during its life-span, the expression and localisation of the major metalloproteinase enzymes, their specific tissue inhibitors and macrophages were investigated. In summary, a model system has been developed and used to study some of the genes and gene products involved in maintenance of the functional and structural integrity of the human corpus luteum. Functional luteolysis beings in the continued presence of the principal components of the steroidogenic pathway. However, as luteolysis progresses, expression of these components is reduced. Structural luteolysis is associated with increased expression of matrix metalloproteinases and an increase in tissue macrophage content. Exposure to hCG during maternal recognition of pregnancy maintains the steroidogenic pathway, and reduces the levels of matrix metalloproteinases and tissue macrophages. As LH receptors are localised to the granulosa-lutein cells this thesis concludes that the effect of luteal rescue on metalloproteinases and macrophages is mediated indirectly by activation or inhibition of specific products of these steroidogenic cells by hCG.
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Park(Takao), Yoomi. "Monoamine oxidase A is highly expressed by the human corpus luteum of pregnancy." Kyoto University, 2009. http://hdl.handle.net/2433/124344.
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Kelly, Christopher Mark 1962. "THE EQUINE CORPUS LUTEUM: IN VIVO AND IN VITRO RESPONSIVENESS TO GONADOTROPIN STIMULATION." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/291492.
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Gonadotropins were used to stimulate luteal function, as determined by progesterone secretion, in both in vitro and in vivo systems. LH and hCG were capable of significantly stimulating progesterone secretion in the in vivo systems. Stimulation of progesterone secretion by hCG was greater than that for LH. PMSG failed to increase progesterone production at any level of treatment. hCG was also used to stimulate progesterone production by the corpus luteum in mares during early gestation. hCG administration resulted in a significant (p < 0.10) increase in peripheral progesterone levels in treatment mares through day 14 post-estrus. Peripheral progesterone concentrations were also higher in hCG treated mares for days 15 through 30 post-estrus in mares that conceived. hCG treatment had no influence on anterior pituitary release of LH.