Teses / dissertações sobre o tema "Prise alimentaire – Régulation"
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Félix, Bernadette. "Régulation nerveuse de la prise alimentaire chez l'oie de race landaise". Paris 6, 1990. http://www.theses.fr/1990PA066501.
Sentissi, El Idrissi Othman. "Régulation neurobiologique centrale et périphérique de la prise alimentaire chez les schizophrènes traités par antipsychotiques : aspects cliniques et biologiques". Paris 6, 2009. http://www.theses.fr/2009PA066107.
Vinera, Jennifer. "Rôle des récepteurs périphériques aux endocannabinoïdes dans la régulation de la prise alimentaire". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1339.
Roux, Julien. "Brain-derived neurotrophic factor (BDNF) et système endocannabinoïde au niveau du complexe vagual dorsal (CVD) : implication dans le contrôle dela prise alimentaire". Aix-Marseille 3, 2009. http://www.theses.fr/2009AIX30065.
BDNF/TrkB signaling and the endocannabinoid system play respectively an anorexigenic and orexigenic role in the central control of food intake. The ventromedical hypothalamus has been identified as a site wher BDNF plays its anorexigenic role, as a downstream effector of melanocortinergic signaling. .
Schoukroun, Florian. "Rôle du noyau tegmental rostromédian dans la prise alimentaire". Electronic Thesis or Diss., Strasbourg, 2023. http://www.theses.fr/2023STRAJ140.
The rostromedial tegmental nucleus (RMTg) is a brain structure projecting to the ventral tegmental area (VTA) and the lateral hypothalamus (LH), two key regulatory centers for feeding behavior. The function of the RMTg remains mostly unknown, and it is plausible that this region plays a role in food intake dysregulation as observed in obesity and binge-eating disorders. We firstly studied the role of the RMTg-VTA and RMTg-LH pathways in food intake regulation through a projection-specific lesional approach followed by a 6-week exposure to an obesogenic diet. Then, we analyzed and compared the adaptations of the endocannabinoid system (ECS), an endogenous system regulating food intake, within reward-related brain regions in obesity and binge-eating disorder models. Our results indicate that the RMTg-VTA and RMTg-LH pathways respectively modulate high-fat and standard food consumption. The molecular analysis revealed distinct dysregulation of ECS expression in obesity and binge-eating disorder, particularly within the RMTg. These findings underscore the involvement of the RMTg and the ECS in pathologies characterized by dysregulated food intake
Coupé, Bérengère. "Impact de la nutrition périnatale sur la programmation du comportement alimentaire : de l'ontogenèse des réseaux hypothalamiques à la régulation de la prise alimentaire". Nantes, 2009. http://www.theses.fr/2009NANT2103.
In neonatology, low birth weight babies (small for gestational age) who suffered of intrauterine growth restriction (IUGR) are fed with protein enriched milk to ensure a catch-up growth and a better verbal intelligence quotient development. However, a catch-up growth after IUGR is correlated with metabolic syndrome associated diseases and with an energy balance regulation impair at adulthood. This observation is known as “foetal and/or postnatal programming”. The mechanisms at the origin of programming are still unknown. We hypothesized that food behaviour alterations could be associate to metabolic disease at adulthood and take place during early postnatal period when hypothalamus ontogeny occurs. The aim of this study was to determine, using IUGR experimental model in rodents induce by protein restriction during foetal life, the impact of a rapid catch-up growth (IUGR pups were nursed by ad-libitum-fed dams or artificial reared with protein enriched milk) on the ontogeny and the regulation of appetite hypothalamic networks. We demonstrated a positive effect of rapid catch-up growth after IUGR on establishment of hypothalamic pathways and on appetite regulation at weaning. However, food behaviour and metabolic parameters during a refeeding period were impaired in adult IUGR rats. These alterations seem to be programmed in utero. Our results indicate an alteration of food behavior which could be an important factor in the way to develop metabolic disorders
Atgié, Claude. "Prise alimentaire et niveau de l'activité adrénergique périphérique chez un rongeur hibernant, le Lérot Eliomys quercinus L". Toulouse 3, 1990. http://www.theses.fr/1990TOU30059.
Romer, Michael. "Sensations hédoniques impliquées dans le contrôle de la prise alimentaire chez l'homme : alliesthésie alimentaire et Rassasiement sensoriel spécifique". Phd thesis, Université de Bourgogne, 2011. http://tel.archives-ouvertes.fr/tel-00728852.
Bariohay, Bruno. "Implication du Brain-Derived Neurotrophic Factor (BDNF) au niveau du Complexe Vagal Dorsal (CVD) dans le contrôle de la prise alimentaire". Aix-Marseille 3, 2007. http://www.theses.fr/2007AIX30018.
BDNF has been implicated as an anorexigenic factor in the central regulation of food intake. In the present work, we identify the DVC as a key site where BDNF plays its anorexigenic role, downstream of melanocortinergic signalling. In the adult rat, we show that central application of exogenous BDNF at the DVC level induces anorexia and body weight loss, whereas endogenous BDNF protein content in the DVC is modulated in a manner consistent with an anorexigenic role, during the dark/light cycle, as well as following experimental paradigms affecting nutritional status or implying leptin, CCK or ghrelin treatments. In addition, we show that 4th ventricle administration of agonists or antagonists for type 3/4 melanocortinergic receptors (MC3/4R) induces respectively an increase and a decrease in BDNF protein content, whereas the orexigenic effects of the MC3/4R antagonist are blocked by a co-treatment with exogenous BDNF
Baraboi, Elena-Dana. "Glucagon-like peptide 1 et peptide YY : activation neuronal et contrôle de la prise alimentaire chez le rat". Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27813/27813.pdf.
Penke, Zsuzsa. "Stress néonatal et régulation à long terme de la prise alimentaire chez le rat : explorations neuroendocriniennes, morphofonctionnelles et comportementales". Nancy 1, 2002. http://docnum.univ-lorraine.fr/public/SCD_T_2002_0250_PENKE.pdf.
The aim of this work was to study immediate and persistent effects of a neonatal stress (maternal deprivation) on the hypothalamo-pituitary-adrenal (HPA) axis and on the food intake in the rat. Experimental rat pups were placed in an incubator either on the 5th or the 14th postnatal day (DEP5 or DEP14 treatment); control rats were not separated from the mother. Maternal deprivation induced no HPA response on the 5th postnatal day, but it activated the HPA axis on the 14th postnatal day. In adults, a diminution of the corticosterone feedback appeared in DEP5 rats in a stressful situation, whereas a transitory increase of the ACTH response was observed in DEP14 rats. We show for the first time that the perturbation of neonatal maturation modifies persistently feeding behaviour, and this modification depends on the age at which deprivation is experienced. Both DEP groups had a diminished basal food intake and an increased anorexic response to dexnorfenfluramine. DEP5 rats had also a decreased preference for carbohydrates, an increased hedonic response, and a decreased anorexic response to dexfenfluramine. The anorexic response of DEP14 rats to restraint stress was increased. Our results, showing a connection between maternal deprivation and disturbed feeding behaviour as well as anxiety, support the hypothesis according to which early stress increases vulnerability to many psychiatric diseases, such as anorexia nervosa and depression. In the future, maternal deprivation can become a useful model for the research into human eating disorders
Kappeler, Laurent. "Vieillissement neuroendocrinien du complexe hypothalamo-hypophysaire chez le rat : criblage moléculaire, axe somatotrope et régulation de la prise alimentaire". Paris 5, 2004. http://www.theses.fr/2004PA05N033.
Influence of neuroendocrine ageing of hypothalamus-pituitary complexe was evaluated by macroarray in Spague Dawley rats which develop obesity and pituitary tumor with age. We observed a decrease and increase of energy expenditure in aged and tumor bearing animals, respectively. The differente life span between strains suggest modified ageing process. We looked for predictive parameters in differents strains, some of them in two nutritional status (fed and 72h fasted). Only the Lou C rat strain was different for some parameters. Morevoer, it did not develop obesity and diseases with age, and have a longer life span. We studied this strain as the Wistar rat strain, whose Lou C rats derived. We have observed in this study a decrease of energy expenditure in the Wistar rats too but an increase in Lou rats
Michau, Aurélien. "Invalidation et activation du transcepteur des sucres GLUT2 : impacts sur la régulation de la prise alimentaire et la sécrétion d'insuline". Paris 6, 2011. http://www.theses.fr/2011PA066532.
Faton, Sina. "Le récepteur 5-HT2c : lien entre activité locomotrice et prise alimentaire". Thesis, Montpellier, 2016. http://www.theses.fr/2016MONT3508/document.
Central serotonin systems have long been associated with the control of ingestive behavior, and the modulation of behavioral effects of psychostimulants.The 5-HT2C receptor is present in hypothalamic centers particularly the arcuate nucleus (ARC) controlling homeostatic regulation of food intake as well as in the ventral tegmental area (VTA), a region important for motivational aspects of multiple behaviors, including feeding.In the present study, the hypothesis was tested that the 5-HT2CR in the VTA may control amphetamine-evoked locomotor activity and 5-HT2CR in the ARC may regulate food consumption. Localized microinjections into the VTA or into the ARC were used to assess the effects of a highly selective 5-HT2C agonist, AR231630, on the locomotor stimulant effect of amphetamine as well as food intake. In the tests for locomotor activity, AR231630 into the VTA, but not into the ARC, dose-dependently reduced locomotor activity elicited by amphetamine. Unexpectedly, in tests for food intake, intra-ARC injection of AR231630 did not reduce food intake even at doses of 10ug, whereas intra-VTA injection of 10ug AR231630 did. A subsequent experiment determined that the suppressant effect of peripheral administration of AR231630 (5 mg/kg) on feeding was partially reversed by pretreatment with the selective 5-HT2CR antagonist SB242084 into the VTA (5ug). These findings suggest that 5-HT2CR in the VTA participates in both food intake and brain reward function, and possibly through the same pathway
Orozco-Solis, David Ricardo. "Étude des modifications fonctionnelles et épigénétiques induites par la dénutrition périnatale sur les circuits cérébraux de régulation de la prise alimentaire". Nantes, 2009. http://www.theses.fr/2009NANT2060.
The main objective of the present work was to determine the influence of the early nutritional environment on the functioning of the hypothalamic neuronal networks regulating food intake and energy homeostasis. The conceptual framework for this research is the thrifty phenotype hypothesis which postulates that in response to nutrient restriction during perinatal development an organism makes metabolic adaptations to survive optimally in a poor nutrient environment. However, when nutrition is adequate or overabundant, the conflict between the metabolic programming and the new nutritional conditions leads to obesity, insulin resistance and hypertension. More precisely, the aims of the present work were: 1) to identify and characterize the effects of protein restriction during gestation and lactation on feeding behavior; 2) to determine if these alterations are associated to epigenetic modifications. The results of the first part of our work indicate that: 1) perinatal protein-restriction leads to increased food intake in relation to body weight during the first six weeks after weaning and accelerates body weight gain; 2) the hyperphagia exhibited by young undernourished animals is characterized by a delayed appearance of satiety, an increase in meal size and reduced latency to eat as well as by an enhanced hypothalamic expression of the orexigenic peptides AgRP and NPY and a reduction in the expression levels of the mRNA coding for the anorexigenic peptide POMC; 3) protein restriction during perinatal development attenuates the inhibitory action of serotonin on food intake via a reduced sensitivity of 5-HT1B Collectively, these results indicate that the higher food intake of young undernourished rats relative to control animals is the result of both a decreased action of negative feedback signals critical to meal termination and an enhanced function of the positive signals than initiate and maintain eating. However, the fact that under conditions of exposure to standard chow, old animals exposed to protein-restriction during perinatal development consume daily the same amount of food than control offspring but exhibit body composition and metabolic disturbances indicative of obesity, suggests that perinatal malnutrition programmes obesity through a mechanism independent of its effects on feeding behaviour. This hypothesis is further sustained by the analysis of the hypothalamus transcriptome in 180 days-old rats which indicate that the programming of the hypothalamic circuits regulating energy homeostasis rather than food intake is a key step in the development of obesity associated with malnutrition in early life. Our receptors; 4) feeding a low-protein diet during gestation and lactation induces a long-lasting disruption of the diurnal expression pattern of the canonical circadian clock genes CLOCK, BMAL1 and Period1 as well as that of several genes involved in the regulation food intake. These effects persist long time after weaning and are associated with hyperphagia; 5) in spite of the fact that since the age of 2 months the offspring of protein-restricted dams consume the same quantity of food by day than their control counterparts, at 8 months, perinatal-undernourished rats show metabolic and body composition disturbances indicative of obesity including elevated levels of triglycerides and fatty acids in serum along with increased visceral fat; 6) a comparative genome wide analysis of the transcriptome in the hypothalamus of metabolic programmed rats versus controls, showed that that perinatal undernutrition induces permanent changes in the transcriptional profile of two gene clusters. The first one is constituted by several genes of the insulin and leptin signaling pathway which, additionally, act as gate keeper genes for regulation of nutrient sensing. The second cluster encompasses a functional network of nuclear receptors and co-regulators of transcription involved in the detection and use of lipid nutrients as fuel which, in addition, link temporal and nutritional cues to metabolism trough their tight interaction with the circadian clock. 12 observations constitute also the first direct evidence that the circadian clock is submitted to metabolic programming. Concerning the second part, as a first attempt to delineate the epigenetic changes induced by early malnutrition on the neuronal circuits regulating food intake, we analyzed the epigenetic status of Histone 3 (H3) and Histone 4 (H4) in several brain regions of 35 days-old offspring born to Spraguey-Dawley rats fed either a control (20%) or a low (8%) protein diet from the day of conception throughout gestation and lactation. Miniaturized protein arrays of histones from the hypothalamus, brain stem, hippocampus, and cerebral cortex of both control and undernourished animals were constructed and screened with anti-H3 or anti-H4 antibodies recognizing epigenetic modifications associated either with increased or with decreased gene transcription. The results of these experiments indicate that perinatal protein-restriction induced significant changes in the acetylated and methylated status of both H3 and H4 that differed from one brain region to another. Interestingly, the epigenetic modifications observed in the hypothalamus of malnourished animals are globally related to active gene transcription. In line with the results of the transcriptome analysis, the genome-wide high throughput study of DNA methylation in the hypothalamus using the methodology of ChIP on chip, indicated that perinatal undernutrition alters essentially the methylation levels of the promoter regions of the genes involved in the regulation of metabolic process
Mahaut, Stéphanie. "Mode d'action des messagers de la famille du neuropeptide Y dans le complexe vagal dorsal de rat en relation avec la régulation de la prise alimentaire". Aix-Marseille 3, 2009. http://www.theses.fr/2009AIX30051.
The neurotransmitter Neuropeptide Y (NPY) and the hormones Pancreatic Polypeptidc (PP) and Peplide YY [3-36] (PYY 3-36) are related messengers (Y-peptides family) that exert mighty control on feeding behavior. The dorsal vagal complex (DVC) is the reflex centre of satiety, i. E. The major short-term feedback m food intake regulation. The DVC contains a high concentration of Y peptide receptors, including a recently identified subtype which is not expressed in hypothalamus, i. E. The major centre of long-term food intake regulation. I have first updated the distribution of all Y receptor subtypes in DVC, by radioactive ligand binding and autoradiography on rat brainstem sections. In order to evaluate their possible involvemeni in food intake regulation, I have assessed the effect of two well-characterized nutritional adaptations on these receptor distributions. Fasting and inflammatory anorexia both decreased tissue concentrations of Yx and Y2 binding sites in area postrema. Endogenous ligands of these receptors being respectively PP and PYY 3-36, I have addressed in vivo whether injection of these peptides in the IVth ventricle, i. E. In the vicinity of DVC, or in periphery would modulate food intake and/or DVC concentration of the anorexigenic mediator Brain-Derived Neurotrophic Factor (BDNI7). My results bring out progress for both NPY pharmacology and DVC specific role in central integration of food intake regulatory agents
Lopez, Carlos Andres. "Mécanismes de contrôle de la prise alimentaire par le système de l'hormone de la mélano-concentration (MCH) : importance des récepteurs opioïdes". Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/29807/29807.pdf.
The brain melanin-concentrating hormone (MCH) system plays an important role in the regulation of energy balance. The sites and mechanisms of the orexigenic action of the MCH are still uncertain. Knowing the function of the NAcSh in the regulation of reward and pleasure, we hypothesize that MCH agonism in the NAcSh increases the pleasure associated with food intake through the opioid neurons within NAcSh. The presence of MCH receptor (MCHR1) on dynorphin and enkephalin neurons of NAcSh supports this hypothesis. Two different experiments in Wistar male were conducted. Firstly, we measured the capacity of three different opioid antagonists injected in the lateral ventricle at doses of 10 nmol and 40 nmol (for κ and δ) or of 10 nmol and 50 nmol (for µ) to block the increase in food intake induced by MCH injection in the lateral ventricle. The rats pretreated with a microinjection of an opioid antagonist 90 min (for the κ and δ) or 22 h (for µ), received a MCH or vehicle injection. Food intake was monitored during one, two and three hours after MCH or vehicle injection. We found that the blockade of opioid receptors by selective antagonists decreased MCH-induced feeding. Secondly, we assessed the level of pleasure in response to sweet stimulus (one milliliter of a sucrose solution, intraoral) by quantifying facial mimics induced by the presence of sucrose in the mouth. The hedonic responses were monitored, 15 min after the injection of a MCH agonist in the lateral ventricle. The same taste reactivity test was repeated following the injection of MCH in the presence of κ, δ and opioid antagonists. We found that the three opioid antagonists were capable of modifying the increased hedonic response induced by MCH by attenuating the positive hedonic properties of sucrose solution. Our results indicate that the orexigenic and hedonic effects of MCH are linked to three opioid receptors. MCH might activate a specific opioid receptor subtype (κ, µ) for exerting its effects on food intake. The interaction of the MCH and opioids systems could represent an important link in the modulation of the hedonic appetite control.
Theysgeur, Sandy. "Propriétés biologiques d’hydrolysats protéiques en relation avec la régulation du métabolisme énergétique". Thesis, Lille, 2019. http://www.theses.fr/2019LIL1R026.
The increase in the world population and the improvement in living standards mean that the demand for animal protein is expected to double by 2050. This will result in an increase in the surface area of agricultural land, with negative effects on climate and biodiversity. There is an urgent need to better qualify agri-food proteins and diversify their sources to address the problems associated with global protein demand. The pet food market is also growing steadily, due to the increase in the population of dogs and cats, and an increasingly humanized relationship between the owner and the animal. As a result, living conditions have evolved, ultimately possibly leading to metabolic disorders in cats and dogs. Gastrointestinal digestion of proteins has long been considered exclusively for its role in providing amino acids; nevertheless, many studies have shown the involvement of protein-derived bioactive peptides, generated during digestion, in many biological functions such as energy homeostasis. They modulate the secretion of intestinal hormones such as cholecystokinins (CCK) and Glucagon-Like Peptide 1 (GLP-1), which are short-term signals involved in the regulation of food intake. The main objective of this thesis was to measure the effects on the regulation of energy homeostasis of two protein hydrolysates, resulting from prior screening (a fish source, PWF and a meat source, XVP 15035), intended for the pet food applications. As a first step, an in vitro gastrointestinal digestion model simulating dog digestion was developed. A study was then conducted to characterize the fate of hydrolysates during in vitro digestion and to determine the effect of these digestates on the regulation of short-term food intake, both by their ability to regulate the secretion of CCKs and GLP-1 produced by enteroendocrine cells, and by their ability to inhibit the activity of the enzyme dipeptidyl peptidase-4 (DPP-IV) modulating GLP-1 activity.Novel bioactive peptides able to stimulate the secretion of intestinal hormones and to inhibit the DPP-IV activity were then identified using separation methods coupled with mass spectrometry. An in vivo study, conducted in parallel in high-fat diet fed rats, revealed in particular the inhibitory effect of PWF hydrolysate on short term food intake
Lenglos, Christophe. "Le système relaxine-3/RXFP3 dans la régulation de la prise alimentaire : effet de la diète, du stress et du facteur sexe". Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26480.
Hyperphagia and obesity are major problems in our society that affect differentially men and women. Therefore, it is necessary to seek the physiological basis of these health problems using animal models such as stress-induced hyperphagia and diet-induced obesity (DIO) in rats, taking into account diet, stress and sex factors. Investigating the role of the orexigenic neuropeptide relaxin-3 appears to be promising because of its involvement in the regulation of stress and food intake. First, we studied the role of relaxin–3 system in DIO rat model. These rats are hyperphagic and defend their elevated body weight against caloric restriction. The results of this study showed higher expression of relaxin-3 in the DIO rats in free feeding conditions, and, in addition, refeeding after food deprivation led to increased expression of the cognate receptor of relaxin-3 RXFP3 in DIO rats suggesting that relaxin-3 is involved in the defense of elevated body weight in the DIO phenotype. In the second study, hyperphagia was developed in female but not male rats submitted to repeated episodes of food restriction and stress. We observed that female hyperphagic rats showed increased expression of relaxin-3 which could be a cause of this sexually specific behavior. In the third study, by the central injection of relaxin-3 in male and female rats, we showed that female rats were more sensitive to lower doses of relaxin-3 and demonstrated higher increase in food intake compared to male rats. We also observed a greater stimulation of the hypothalamic pituitary adrenal (HPA) axis in male rats that may limit the orexigenic effect of relaxin-3. Conversely, in female rats, stimulation of corticotropin-releasing factor expression in the bed nucleus of the stria terminalis may enhance feeding behavior. In summary, our work demonstrates the role of relaxin-3/RXFP3 system in hyperphagia and body weight gain and shows its sex-specific effects in food intake regulation and stress response.
Ronveaux, Charlotte. "Mécanisme des hormones anorexigènes régulant la prise alimentaire au niveau du nerf vague". Thesis, Paris, AgroParisTech, 2015. http://www.theses.fr/2015AGPT0002/document.
As the initial interface for nutrient sensing, digestion and absorption, the gastrointestinal (GI) tract plays a critical role in the regulation of energy homeostasis. Information that arises from the GI tract is key to normal physiological responses controlling gut function and regulating food intake. Vagal afferent neurons (VAN) are a major pathway by which information about ingested nutrients reaches the central nervous system to influence GI function and food intake behavior. VAN express receptors for many of the regulatory peptides released from the gut that are involved in regulation of food intake and body weight. This dissertation addresses the role of two gut peptides, leptin and glucagon-like peptide-1, acting at the level of VAN, to inhibit food intake. First, the mechanism of action of glucagon-like peptide-1 (GLP-1) on VAN is addressed. GLP-1-induced satiation requires a postprandial state; the data support that feeding changes the localization of GLP-1Rs from the cytoplasm to the neuronal cell membrane. Further, ghrelin and its receptor GHSR1 expressed by VAN is involved in regulating GLP-1 receptor translocation. Second, the importance of leptin receptor expression by VAN in the development of hyperphagia and obesity was demonstrated by selective knockout of the leptin receptor (LepR) in VAN; mice express an obesogenic phenotype. Obesity and its resultant health consequences are a major worldwide health problem. Effective or preventative treatments for obesity are limited. Our findings have filled the gap in our knowledge of the mechanism of GLP-1 and leptin signaling on VAN. Understanding the physiology regulating feeding behavior is imperative in developing non-invasive anti-obesity treatments
Laurent, Laetitia. "Implication de l'activité constitutive des récepteurs 5-HT4 dans la régulation de la conduite alimentaire : vers une solution thérapeutique". Thesis, Montpellier 1, 2011. http://www.theses.fr/2011MON1T035.
Feeding behavior does not necessarily obey to the physiological need to eat (hunger) or to satiety, suggesting that voluntary nervous system of the restriction (anorexia) and overeating (bulimia, binge-type eating) inhibits the autonomic nervous system. These two anomalies affecting more frequently, and often both, the woman than man. If animal models are used to study a part of neural bases involved, those possibly responsible for the oscillation of"anorexia / bulimia" remain to be identified. In this context, we thus focused our analysis on the study of the involvement of brain receptors coupled to G proteins ; serotonin 4 receptors (5-HTR4) because their stimulation in the nucleus accumbens (NAc), a brain reward area, inhibits hunger even after a food deprivation, by the action ofcAMP / PKA, dependent of an addiction peptide, "cocaine-and amphetamine-regulated transcript" (CART). Weshow that maintaining a higher expression (ectopic or physiological) of 5-HTR4 in the NAc, reduced hunger more longer than the acute stimulation and increased locomotor activity. Including in our reasoning the constitutive activity of 5-HTR4 (e.i. accumulation of the active form R*), we show that injecting a specific inverse agonist of the5-HTR4 (inhibition of constitutive activity: accumulation of inactive form, R ) in the NAc induced a decrease incAMP and CART levels, while increasing NPY mRNA level, especially when binge is high. The effects induced by the injection of the inverse agonist are not observed when a 5-HTR4 antagonist was coadministrated. These results suggest a physiological involvement of the constitutive activity of 5-HTR4 in the regulation of feeding behavior ; its inhibition (inverse agonist) in the NAc increases the food intake in fed or food-deprived mice. All of these results makes it likely that the highest activity of 5-HTR4, at the base of the association "anorexia /locomotor hyperactivity", often described as paradoxical in terms of energy, in the syndrome of anorexia nervosa,represent rather a global compensation mechanism of energy to be lost as a result of an excessive consumption of food. Since the density of the 5-HTR4 may vary depending on a variable rate of 5-HT following stress, which aggravates the feeding disorders, we further investigated the involvement of 5-HTR4 in the appetite-suppressant effect of stress (forced immobilization) in female mice deprived of their gene: stress-induced hypophagia was not observed in mice deprived of 5-HTR4 who present a possible hyperactivity of the hypothalamic-pituitary adrenocortical axis likely offset by a stronger negative feedback. It is therefore likely that the 5-HTR4 contribute to reduce the effects of stress and that the modification of the balance of their activities contribute to a part of the symptoms of patients with anorexia / bulimia
Haissaguerre, Magali. "Etude de l’intéraction entre les ros et la voie mtorc1 dans la régulation de la balance énergetique". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0206/document.
The mechanistic target of rapamycin complex 1 (mTORC1) pathway is an importanthypothalamic integrator of nutrients and hormones. Nutrient availability also affects thereactive oxygen species (ROS) in propiomelanocortin (POMC) neurons and regulatesneuronal activity. We hypothesize that modulation of mTORC1 activity mediates ROS effectson food intake.To this purpose, C57Bl6J mice or WT mice and their KO littermates either deficient for themTORC1 downstream target S6K1 or for the mTORC1 component raptor specifically inPOMC neurons (POMC-raptor-KO) were treated with an intracerebroventricular (ICV)injection of the ROS producer H2O2 or the ROS scavenger honokiol, alone or in combinationwith the mTOR inhibitor rapamycin or the mTOR activator leptin.ICV H2O2 induced phosphorylation of S6K1 within the hypothalamus, increased expressionof c-fos, a marker of neuronal activity, in the arcuate nucleus and increased ROS in POMCneurons. These effects were associated with a significant decrease in food intake. Theanorexigenic effect of ICV H2O2 was not seen in S6K1-KO mice, in C57Bl6J mice cotreatedwith rapamycin (an mTOR inhibitor) and in POMC-raptor-KO mice.Similarly, ICV honokiol administration combined with a leptin injection blunted theanorexigenic effect of leptin, suggesting that leptin requires ROS formation to reduce FI. ICVadministration of leptin increased ROS in POMC neurons in C57Bl6J and POMC-raptor-WTmice, but not in POMC-raptor-KO mice.Our results demonstrate that ROS modulators require a functional mTORC1 pathway toregulate food intake and that leptin needs an mTORC1-dependent increase in ROS levels inPOMC neurons to decrease food intake
Langlet, Fanny. "Etude de l'interface sang-noyau arqué hypothalamique au cours d'un déséquilibre énergétique : plasticité de l'éminence médiane et impact sur la régulation de la prise alimentaire". Phd thesis, Université du Droit et de la Santé - Lille II, 2013. http://tel.archives-ouvertes.fr/tel-00965922.
Hassouna, Rim. "Rôles des peptides dérivés de la préproghréline dans le contrôle de la sécrétion de GH et du comportement alimentaire". Phd thesis, Université René Descartes - Paris V, 2012. http://tel.archives-ouvertes.fr/tel-00781915.
Bonnet, Marion. "Implication des neurones exprimant NUCB2/nesfatine-1 dans la régulation de l'homéostasie énergétique". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4310/document.
The long term maintenance of body weight results from a balance between energy expenditure and intake. This balance, called “energy homeostasis”, involves a large number of molecules. Among these, nesfatin-1, discovered in 2006, is an 82 amino-acid peptide derived from the cleavage of the protein NUCB2. The interest generated by nesfatin-1 lies in its anorexigenic effect performed independently of leptin signalization. Nesfatin-1 is expressed in several organs such as adipose tissue, stomach, pancreas, and brain. In the brain, its expression is limited to a few neuronal groups located in the hypothalamus and dorsal vagal complex. In this work, we analyzed the sensitivity of NUCB2/nesfatin-1-expressing neurons to physiological and physiopathological peripheral signals affecting food intake. We show that these neurons are sensitive to hypoglycemia and that they could contribute to the counter-regulatory response established in order to restore the basal blood glucose level. Moreover, we show that they are activated in response to two inflammatory stimuli: lipopolysaccharide administration and food intoxication with a mycotoxin named deoxynivalenol. So, NUCB2/nesfatin-1-expressing neurons could contribute to the development of inflammatory anorexia. This study was the first evidence of an involvement of this peptide in a pathological situation. Taken together, these results suggest that in addition to its satiating effect, nesfatin-1 participates in the central signalization involved in glucodetection and inflammatory responses
Tolle, Virginie. "La ghreline, une nouvelle hormone gastrointestinale se liant au récepteur des GH sécrétagogues : du contrôle de la sécrétion de l'hormone de croissance (GH) à la régulation de la prise alimentaire et des rythmes veille/sommeil". Paris 6, 2002. http://www.theses.fr/2002PA066353.
Bellocchio, Luigi. "Rôle du récepteur cannabinoïde de type 1 sur des populations neuronales spécifiques dans la régulation de l'équilibre énergétique". Thesis, Bordeaux 2, 2010. http://www.theses.fr/2010BOR21736/document.
The endocannabinoid system (ECS) has recently emerged as an important modulator of foodintake and energy balance. Cannabinoid type-1 (CB1) receptor and endogenous ligands, 2-arachidonoyl-glycerol (2-AG) and anandamide (AEA), are largely present in the brain and inperipheral organs involved in the regulation of energy metabolism, such as liver, adiposetissue, skeletal muscle, pancreas and GI tract. Pharmacological CB1 stimulation generallyleads to an increase in energy intake and storage, whereas CB1 antagonists exert the oppositeeffects in both animals and humans. Furthermore, there is evidence of correlations betweenpathological ECS up-regulation and metabolic diseases.However, several pieces of evidence indicate that the relationship between the ECS andenergy intake and metabolism might be more complex than previously believed, likely due tothe different sites where the ECS could act in the body. The general aim of this Thesis workwas to dissect the different mechanisms through which the ECS regulates food intake andenergy balance. The first Chapter of this Thesis is an overview of the neuronal mechanismsregulating energy balance in mammals. In Chapter II, we analysed the brain neuronal typesresponsible of the impact of CB1 signalling on stimulated food intake. Chapter III, reveals thatthe pharmacological blockade of CB1 exerts anorectic effect acting at peripheral sympatheticneurons. Then (chapter IV) we dissected the possible impact of neuronal CB1 onto energybalance.CB1 antagonists were shown to exert only transient anorectic effects, which disappear afterfew weeks of treatment in animals and few months in obese patients. Furthermore, CB1agonists show typical biphasic effects, with low-to-moderate doses increasing food intake inanimals, and high doses decreasing ingestive behaviour. CB1 is expressed in many differentneuronal populations, including GABAergic and cortical glutamatergic neurons. As thegeneral effect of CB1 activation is a reduction of neurotransmitter release, it is possible thatthese apparently discrepant effects of pharmacological manipulations are due to thedifferential expression of the receptor. By using combined pharmacological and geneticapproaches we found that ventral striatal CB1 receptors are endowed with a hypophagicimpact through inhibition of GABAergic transmission. Conversely, brain CB1 receptorsmodulating excitatory transmission mediate the well-known orexigenic effects ofcannabinoids (Chapter II).The acute injection of CB1 antagonist SR141716 (Rimonabant) has an important anorecticeffect in condition of stimulated food intake, such as fasting-induced hyperphagia. However,the nature of this effect (central versus peripheral) as well as the neuronal circuits involved isstill matter of investigation. In Chapter III we show that rimonabant-induced hypophagia isindependent from CB1 modulation of GABAergic, cortical glutamatergic and serotoninergictransmission in the brain, as well as intrinsic actions of CB1 in different hypothalamic nuclei.In fact, rimonabant inhibits stimulated food intake by directly enhancing peripheralsympathetic actions.In relationship to metabolic functions of the ECS, it is not yet clear whether CB1 receptorsexpressed on neurons or on peripheral metabolic organs play a major role in the control ofenergy storage and consumption in both physiological and pathological conditions. In thisscenario, in Chapter IV, we show that neuronal CB1 receptors play a key role in thedevelopment of diet-induced obesity. Conditional mutant mice lacking CB1 expression inforebrain neurons and sympathetic peripheral neurons, known to control food intake and bodyweight, but not in peripheral organs, displayed a lean phenotype and resistance to diet-inducedobesity. This phenotype results from an increase in lipids oxidation and thermogenesis and adecrease in energy absorption due to an increase of the sympathetic tone.As discussed in the Chapter V, neuronal CB1 signalling is a key determinant of the ECSaction on energy balance, by exerting a bimodal control of feeding behaviour and byregulating energy expenditure and sympathetic nervous system activity. The differencesbetween the role of endogenous versus exogenous CB1 agonists, as well as between agonistsversus antagonists suggest that this receptor may have different pharmacological propertiesaccording to the cell type-specific signalling involved
Lepoittevin-Bergeot, Nathalie. "Régulation de la prise alimentaire des vaches laitières en relation avec les variations des réserves lipidiques : rôle des agonistes béta-adrénergiques, de l'insuline et de l'hormone de croissance". Rennes 1, 1996. http://www.theses.fr/1996REN10030.
Theysgeur, Sandy. "Propriétés biologiques d’hydrolysats protéiques en relation avec la régulation du métabolisme énergétique". Electronic Thesis or Diss., Université de Lille (2018-2021), 2019. http://www.theses.fr/2019LILUR026.
The increase in the world population and the improvement in living standards mean that the demand for animal protein is expected to double by 2050. This will result in an increase in the surface area of agricultural land, with negative effects on climate and biodiversity. There is an urgent need to better qualify agri-food proteins and diversify their sources to address the problems associated with global protein demand. The pet food market is also growing steadily, due to the increase in the population of dogs and cats, and an increasingly humanized relationship between the owner and the animal. As a result, living conditions have evolved, ultimately possibly leading to metabolic disorders in cats and dogs. Gastrointestinal digestion of proteins has long been considered exclusively for its role in providing amino acids; nevertheless, many studies have shown the involvement of protein-derived bioactive peptides, generated during digestion, in many biological functions such as energy homeostasis. They modulate the secretion of intestinal hormones such as cholecystokinins (CCK) and Glucagon-Like Peptide 1 (GLP-1), which are short-term signals involved in the regulation of food intake. The main objective of this thesis was to measure the effects on the regulation of energy homeostasis of two protein hydrolysates, resulting from prior screening (a fish source, PWF and a meat source, XVP 15035), intended for the pet food applications. As a first step, an in vitro gastrointestinal digestion model simulating dog digestion was developed. A study was then conducted to characterize the fate of hydrolysates during in vitro digestion and to determine the effect of these digestates on the regulation of short-term food intake, both by their ability to regulate the secretion of CCKs and GLP-1 produced by enteroendocrine cells, and by their ability to inhibit the activity of the enzyme dipeptidyl peptidase-4 (DPP-IV) modulating GLP-1 activity.Novel bioactive peptides able to stimulate the secretion of intestinal hormones and to inhibit the DPP-IV activity were then identified using separation methods coupled with mass spectrometry. An in vivo study, conducted in parallel in high-fat diet fed rats, revealed in particular the inhibitory effect of PWF hydrolysate on short term food intake
Daumas-Meyer, Virginie. "Plasticité morphologique des astrocytes glomérulaires du bulbe olfactif chez le rat : rôle dans la relation entre l'olfaction et la prise alimentaire". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLA019/document.
Olfaction plays a key role in the elaboration of the hedonic value of foods and the regulation of food intake. Reciprocally, the detection of food odors is influenced by the metabolic state. Fasting increases olfactory performances, notably by increasing neuronal activity in the olfactory bulb (OB). Within the OB glomeruli, the glutamatergic synapses between olfactory sensory neurons and mitral cells are regulated by astrocytes, periglomerular neurons and centrifugal afferents. Astrocytes, which support mecanisms of metaplasticity in the brain, may drive the metabolic regulation of the olfactory response in the OB. To test whether OB glomerular astrocytes are involved in the metabolic sensing of the olfactory system, we compared the astroglial processes expansion by quantification of the GFAPlabelled area in fed and fasted rats.Astroglial spreading was markedly increased in fasting rats, as compared to fed rats, in all regions of the OB after 17h-fasting. Intra-peritoneal administration of the anorexigenic peptide PYY3-36 or glucose in 17h-fasted rats respectively decreased their food intake or restored their glycemia and both reversed the increased astroglial deployment induced by fasting. Direct application of orexigenic peptides ghrelin and NPY on OB acute slices, resulted in an increase of the astroglial deployment, whereas application of PYY3-36 oppositely resulted in astroglial retraction within the glomeruli. These results are in close agreement with the effects of fasting or satiation on the morphology of astrocytes.The deployment of the glomerular astroglial processes clearly varies according to the metabolic state of the rats, and is influenced by food intake regulatory peptides. This plasticity may participate in the adaptation of the olfactory sensitivity to food intake
Voinot, Florian. "Axe cerveau-intestin et contrôle de la prise alimentaire : exemple d'altérations chez un modèle animal de schizophrénie". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00790379.
Willem, Clémence. "Déterminants et prise en charge de l’alimentation émotionnelle dans l’obesité : le rôle des troubles de la régulation émotionnelle, des déficits de conscience intéroceptive et de la sévérité de l’obesité". Thesis, Lille 3, 2020. http://www.theses.fr/2020LIL3H028.
Emotional eating is a problematic eating behavior that promotes the development and maintenance of obesity. The aim of this thesis is to better understand the psychological mechanisms involved in the emotional eating of people with obesity. It is organized around four experimental studies. The first three studies examine how emotion regulation disorders, deficits in interoceptive awareness and emotional eating manifest and interact in obesity. The fourth study assesses the impact, and effectiveness, of a therapeutic intervention focused on emotional regulation.The four studies of this thesis highlight that emotional regulation disorders and deficits of interoceptive awareness are major and associated risk factors of emotional eating in obesity, which need to and can be jointly addressed.Our work (1) confirms the co-occurrence of emotion regulation disorders and deficits in interoceptive awareness in moderate and severe obesity; (2) highlights a mediating effect of emotion regulation disorders in the relationship between interoceptive awareness deficits and emotional eating in obesity; (3) underline the importance of interoceptive reliability, as the relationship that peoples have with their inner body sensations; (4) show that the links between emotion regulation disorders, depressive symptoms, anxiety symptoms and emotional eating differ depending on the severity of obesity; (5) confirm that emotion regulation training (ART program) can significantly reduce emotional eating in obese patients.These studies also offer numerous research prospects and open up various clinical applications, which will be discussed
Fleury, Léa. "Etude comparative de l'implication des protéines alimentaires dans l'homéostasie énergétique". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2022/2022ULILR028.pdf.
In addition to being a source of essential nutrients for our body, dietary proteins participate in the regulation of energy homeostasis. In a context of obesity epidemic and food overconsumption, the characterization of the role of proteins on health becomes crucial. In general, proteins are known to reduce food intake by stimulating satiety and improving glucose homeostasis, but very few studies have focused on comparing the effects of protein origin on these phenomena. The objective of this work is to compare proteins of different origins on certain homeostasis mechanisms involved in the peripheral regulation of food intake and glucose metabolism. Proteins from various sources of animal or plant origin were thus selected: bovine hemoglobin, caseins, ovalbumin, whey, fish gelatin, peas and gluten. These proteins were first studied and compared in vivo in rats. A first study using metabolic cages determined the effect of proteins on short-term food intake, energy expenditure, gas exchange coefficient, and locomotor activity. A second study investigated the effect of proteins on the regulation of intestinal glucose absorption, on the modulation of the secretion of intestinal hormones and on the inhibition of the DPP-IV (Dipeptidyl peptidase IV) activity and a third study was carried out to determine the effect of proteins on glucose homeostasis.. In parallel, complementary functional studies were carried out ex vivo on parts of rat intestine and in vitro on different intestinal cell models. The proteins were then digested using a static gastrointestinal digestion protocol suitable for the digestion of proteins alone. The results obtained globally highlight an effect of the protein source on energy homeostasis via different action on the followed markers. This work also highlights, for the first time, that an acute protein intake could improve glucose tolerance by inhibiting its absorption by the intestine. Indeed, protein digests were able to decrease intestinal glucose absorption in vitro and ex vivo and acute ingestion of fish casein and gelatine improved glucose tolerance in rats without significant effect on insulin secretion. All of these studies have highlighted the importance of proteins in the mechanisms for regulating energy homeostasis through their interactions on markers of glucose metabolism and food intake, which are both very closely linked. Proteins, depending on their origin, modulate more or less the secretion of satietogenic and pancreatic hormones, the activity of DPP-IV and the intestinal glucose absorption
Fassier, Philippine. "Alimentation, consommation d’alcool, activité physique, prise de compléments alimentaires, variation de poids et représentations nutritionnelles : évolution avant/apres diagnostic d’un cancer". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCD072/document.
While cancer survivors are at increased risk for negative conditions as second cancers, other comorbidities, and functional decline ; lifestyle factors, such as a healthy diet, regular exercise and weight control, may contribute to prevent these conditions and improve survivors' quality of life. In this context, aims of this thesis were, among cancer survivors from the French prospective NutriNet-Santé study, to 1) investigate nutritional variations between before and after cancer diagnosis as well as dietary supplements use, and 2) evaluate opinions relating to some diet factors and to weight-loss restrictive diets and fasting practices, and to link them on the one hand to their real practices, and, on the other hand, to their sources of nutritional information.In the first part, our results highlight some healthy behaviors such as a decrease in alcohol and sweetened drinks consumption, but also less favorable trends, such as a decrease in vegetable consumption and in many vitamin and mineral intakes. We also observed a decline in overall and vigorous physical activity after diagnosis, especially in prostate and skin cancers, in men and professionally inactive patients. Concomitantly, we observed an increase in sedentary behaviors, especially in women, older subjects and professionally inactive patients. We also observed that while weight loss was reported in many colorectal cancer patients, a substantial proportion of breast cancer patients gained weight. Sociodemographic and economic factors appeared as important determinants of weight gain, illustrating social inequalities in health (higher risk among patients with lower income and lower education). Our results suggest that dietary supplements use was widespread among cancer survivors, a large amount of which being used without any medical supervision, including a non-negligible proportion of patients having dietary supplement practices which can be considered as “at risk”. In a second part, we observed that opinions from cancer survivors regarding some nutritional factors seemed to impact their dietary practices and were themselves impacted by sources of nutritional information. In particular, opinions regarding alcohol consumption were concerning, with an important proportion of cancer survivors who thought that alcohol consumption (and even more regarding red wine) had a positive impact on their disease. Weight-loss restrictive diets were practiced by a large number of cancer survivors since their diagnosis, while fasting was less practiced, but was far from being an isolated phenomenon
Germain, Natacha. "Le profil des hormones de la régulation de l'appétit dans la maigreur". Thesis, Saint-Etienne, 2010. http://www.theses.fr/2010STET014T.
The commonest group of underweight young women in the developed world is restrictive anorexia nervosa (AN). However, constitutional thinness (CT) is a condition described in the same low weight range as AN. CT women display normal menstruation an do not present with psychological or hormonal features of AN. Eating disorders (EA) displays Anorexia Nervosa with restrictive food behaviour (AN-R), Anorexia Nervosa with binge purge associated (AN-BP) and bulimia Nervosa (BN ). Food intake is controlled by the arcuate nucleus through integration of peripheral hormonal signals such as leptin, ghrelin, peptide YY (PYY) and glucagon like peptide 1 (GLP-1). Our objective was to understand thinness and EA through those hormonal signals. AN-R presents an orexigenic adaptative profile contrasting with the anorexigenic constitutive one in CT, proving the integrity of the appetite regulation system. We propose the ghrelin resistance concept with the putative obestatin. AN-BP presents a very different profile of appetite regulatory peptides when compared with AN-R, with low ghrelin levels. The hormones appear to be valuable biomarkers to distinguish AN and CT in severe underweight patients and to diagnose binge purge in AN. The assessment of ghrelin (and eventually obestatin) could be of particular interest for differential diagnosis between AN-R and AN-BP. The assessment of leptin could also be useful for differential diagnosis between AN and CT
Schwarz, Jessica. "Cartographie centrale de la sensibilité interne aux macronutriments". Phd thesis, AgroParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00769585.
Les mécanismes exacts par lesquels les protéines alimentaires influencent la faim et la satiété ne sont pas encore compris. Pour mieux comprendre ces phénomènes, nous avons réalisé 3 études qui constituent le présent travail de doctorat. Tout d'abord, concernant la transmission des informations relatives à la présence de protéines via le nerf vague, une première étude a montré que les afférences vagales de la zone hépato-portale ne sont pas nécessaires pour la dépression de la prise alimentaire induite par un régime HP. Deuxièmement, nous avons comparé les motifs d'activité neuronale dans le DVC en réponse à une charge protéique ou glucidique. L'utilisation de techniques de modélisation et de reconstruction 3D a permis de montrer que les motifs d'activité neuronale par la présence de protéines et de glucides sont spatialement distinctes. Dans une troisième étude nous avons testé l'effet des protéines sur le métabolisme énergétique et sur la réponse à une stimulation inhibitrice de la faim, ce dernier paramètre ne semble pas être significativement modulé par une augmentation de l'apport en protéine de la ration chez la souris.
Ould, Hamouda Hassina. "Impact de la qualité des protéines et des lipides du régime de renutrition sur la composition en acides gras, la réponse hépatique à l'insuline, la régulation de l'homéostasie énergétique et l'inflammation, chez les rats âgés Wistar souffrant de malnutrition". Thesis, Paris 11, 2015. http://www.theses.fr/2015PA11T019/document.
Malnutrition related to aging is often accompanied by many metabolic disorders, including the disruption of energy homeostasis (installation of insulin resistance), fragility, decreased muscle mass and immune response deficiency. Thus, the nutritional manipulation, during aging, is considered to be a solution to prevent these disorders or to treat and limit damages. Amongst the nutrients that have been widely studied, we find the quality of proteins (or amino acids), of lipids (n-3 PUFA) and micronutrients (vitamin D).The aim of this thesis is to determine the impact of undernutrition and assess the potential of the refeeding formulas containing a high content of soluble protein of milk, associated with milk fat enriched with omega3 polyunsaturated fatty acids (ALA precursor and DHA) and vitamin D, on the fatty acid (FA) of the plasma, red blood cells and brain and its consequences on markers of inflammatory status, the hepatic response to insulin, the expression of genes involved in the regulation of energy homeostasis as well as hypothalamic inflammation, in old rats previously submitted for food restrictionAs a first step, our results showed that the dietary restriction of three months, despite being only moderately ALA deficient, induced a drastic loss omega3 (ALA and derivatives LCn-3), whereas a weak increase of ARA derived from n-6 series is observed, leading to a rise of the pro-inflammatory state expressed as an increase in the ratio ARA/LCn-3.However, we have shown that the four-week-refeeding formulas containing a blend of dairy-fat, rapeseed and DHA associated with casein or milk soluble proteins, restored 1 / DHA values of the brain not previously restored by the refeeding control diet, 2 /increases the values of LCn-3 derivatives (EPA, DHA) to levels above those obtained with the control non-malnourished and refeeding diets. This increase was accompanied by a reduction in ARA values, leading to a drastic drop in plasma and red blood cells ratio ARA / EPA. These formulas show for the first time that they can induce a very significant reduction of inflammatory status compared to that usually seen in old rats and could therefore present a more general interest in prevention of ageing diseases associated or not to undernutrition.In a second step, our results showed that dietary restriction of three months resulted 1/increased expression of the insulin receptor in the hypothalamus, liver and adipose tissue, accompanied by an increase of the proinflammatory factor TNF in the hypothalamus. However, the four-weeks-refeeding produces 2/ a similar weight gain and maintains hepatic insulin sensitivity. Indeed, we showed, for the first time, that refeeding, with diets containing the blend of dairy-fat / rapeseed / DHA, would 3/ increase food intake and decrease the hypothalamic inflammation, especially with the full formula containing a mixture of high content of soluble milk proteins, associated with dairy-fat / rapeseed / DHA fortified with vitamin D
Ambli, Mouna. "Identification de nouvelles voies de valorisation en lien avec la santé pour des hydrolysats de collagène d'origines différentes". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR040.
The constant increase in the number of people suffering from obesity and its associated pathologies, grouped under the term metabolic syndrome, urgently requires implementing preventive solutions. Proteins and, more specifically, bioactive peptides, derived from the digestion of these proteins, constitute interesting solutions with very high added value for agri-food companies in a context of valorization of by-products combining health, rational consumption and circular economy. This thesis studied three types of gelatines, beef, pork and fish, and their hydrolysates to investigate their health benefits.All six matrices were subjected to simulated gastrointestinal digestion (SGID), mimicking the first three phases of digestion: oral, gastric and intestinal.The first study focused on the characterization of the matrices by steric exclusion chromatography and mass spectrometry. This step highlighted differences in peptide populations that could lead to differences in bioactivities depending on the matrices digested. Concerning bioactivities, the study focused on the capacity of digests from the intestinal phases to i) induce the secretion of intestinal hormones, ii) inhibit dipeptidyl peptidase-IV (DPP-IV)activity, an enzyme involved in glucose metabolism via the cleavage of incretins such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and iii) reduce the inflammatory status of the intestinal epithelium.The digests were tested on enteroendocrine cells, STC-1, capable of secreting a range of intestinal hormones implicated in regulating food intake and glucose metabolism, such as GLP-1 and cholecystokinins (CCK). Pork gelatine digests have been shown to stimulate the secretion of these hormones significantly.Regarding the inhibition of DPP-IV, several strategies have been used. The first, using in vitro recombinant human DPP-IV, and the second in situ, using an intestinal cell model (Caco-2) expressing the enzyme, revealed that fish gelatine hydrolysate digest is the protein source with the most significant inhibitory power. Two peptide sequences of interest, derived from fish gelatine hydrolysate digest, were successfully identified after passage through the intestinal barrier, simulated using a Caco-2 / HT-29-MTX cell coculture by mass spectrometry analysis and optimization of bioinformatics prediction tools. The peptides were then synthesized and validated as effective in vitro inhibitors of plasmatic DPP-IV in human serum.In an innovative intestinal barrier model, the digested sources were also studied in vitro in the context of inflammation. As a result, some of them reduced the amounts of interleukin-8 secreted by intestinal cells to the same level as the anti-inflammatory control, traducing a decrease in the inflammatory state of the intestinal barrier.These results highlight the bioactivities of the peptides derived from these gelatines, protein by-products of the agri-food industry, which could, in a personalized diet approach, prevent pathologies linked to metabolic syndrome and improve the quality of life of patients. They also contribute to a better understanding of the bioactivity of food proteins at the intestinal level
Yang, Chun. "Sim1 function in the developing and adult brain". Thèse, 2006. http://hdl.handle.net/1866/15227.