Littérature scientifique sur le sujet « Gastro-Intestinal hormones »

A left adrenal mass was incidentally detected in a 61 years old male as he was evaluated for a dysuria. The man had a 20 years-long history of high blood pressure and used to snuff tobacco. All the adrenal hormones were normal levelled but that of the aldosterone. The aldosterone to renin ratio was low. However, the mass turned out to be an extra-adrenal one, typically a stromal tumor pedunculated into the gastric fundus. The urologists should be aware that a gastro-intestinal stromal tumor may misleadingly presents as a left adrenal tumor and consider it especially when an adrenal mass exhibits atypical hormone levels.

Endocrine modulation of various growth and survival mechanisms is at the helm of cellular homeostasis and impaired endocrine balance may potentially galvanize cardiovascular health to go haywire. Melatonin, an effective antioxidant and multipotent hormone has preponderant influence on the activities of several endocrine factors including growth hormones, thyroid hormones, gastro-intestinal hormones, and those controlling reproductive and metabolic functions. Many of these hormones tightly regulate cardiovascular functions while the mammalian heart has its own endocrine machinery. Endocrine disruptions severely affect cardiovascular integrity and hormonal therapies may instigate adverse cardiac events. Therefore, this review focuses on the cardioprotective potential of melatonin concerning endocrine instability-mediated cardiovascular dysfunction. Melatonin has been reported to effectively counteract sympathetic overstimulation and also reduce the cardiotoxic attributes of catecholamines and their derivatives. Melatonin suppresses the pernicious cardiovascular manifestation of thyrotoxicosis and autoimmune thyroiditis, which is possibly attributed to its antioxidant property and regulation of iodothyronine-deiodinase activity. Interestingly, being a circadian synchronizer melatonin potentially preserves the diurnal pattern of insulin secretion and thereby improves glucose tolerance and cardiac GLUT-4 expression. Besides, melatonin modulates insulin signaling pathway by enhancing the activation of insulin receptor-associated tyrosine kinase, thus protecting the heart against diabetogenic outcomes. Further, melatonin has demonstrated its beneficial action against non-dipper hypertension by regulating the RAAS function. However, there is a plethora of unresolved research question that necessitates additional investigation into the potential therapeutic effect of melatonin in endocrine dysfunctions that emanates during various physiological and pathological states and may have potentially harmful cardiovascular implications.

Abstract. Natural Somatostatin has a short half-life (3 min), is only active after intravenous administration and causes a rebound hypersecretion of hormones after discontinuation of administration. Recently a longacting powerful Somatostatin analog was developed (SMS 201-995; Sandostatin) which has a half-life of 113 min after subcutaneous administration. After administration of this analog no rebound hypersecretion of hormones was observed. In the present review the effects of the acute administration and of long-term treatment with SMS 201-995 in acromegalic patients is discussed. In addition the potential role of therapy with Somatostatin analogs and the preliminary effects of Somatostatin and/or SMS 201-995 are discussed in disorders of gastro-intestinal function (haemorrhages, diarrhoea, pancreatitis and endocrine pancreatic tumours), diabetes mellitus, central nervous system disturbances and oncology. Finally, several aspects of the tolerance, tachyphylaxis and side effects of SMS 201-995 are discussed.

Nineteen different antisera raised against mammalian hormones were used to identify the occurrence and distribution of endocrine cells in the gut of grass carp (Ctenopharyngodon idellus). Positive reactions were obtained in gut epithelium with antisera gastrin, glucagon, gastric inhibitory peptide, leucine enkephalin, substance P, and bovine pancreatic polypeptide. No immunoreactive product was formed using antisera against somatostatin, 5-hydroxy-tryptamine, insulin, avian pancreatic polypeptide, motilin, cholecystokinin, secretin, neurotensin, vasoactive intestinal polypeptide, bombesin, neuron-specific enolase, prochymosin, and pepsinogen. The exact distribution mapping of six kinds of immunoreactive endocrine cells throughout the gut of grass carp (C. idellus) is presented. The morphological characteristics of immunoreactive endocrine cells is described. Their distribution characteristics and possible modes of secretion and function are discussed. Finally, the possible relationship between the transplantation of these cells in the gastro-entero-pancreatic endocrine system is discussed.

AbstractAlthough cortisol is a powerful modulator of the immune system and inhibits production of pro-inflammatory cytokines, adrenocorticotropic hormone (ACTH) levels do not correspond to the chronically elevated concentrations of cortisol in cancer patients. Thyroid stimulating hormone (TSH) has been shown to have an effect on immunological functions. Actually it is not known whether cortisol, TSH and IL-6 have an effect on tumor progression via modulation of cell mediated immunity in patients with gastrointestinal carcinoma. Sixty-seven gastrointestinal cancer patients and 42 cancer-free subjects with cholelithiasis as the control group, were included in the study. Serum ACTH, cortisol, TSH, thyroid hormones, IL-6, IL-10 and neopterin levels were measured. Diagnosis and pathological staging were confirmed by surgical intervention. Cortisol levels were correlated with IL-6 in cancer patients. In addition to elevated neopterin values, linear regression analysis revealed that serum neopterin was associated more strongly with the increase of cortisol rather than IL-6 levels in advanced stage carcinoma. Furthermore, neopterin also correlated with IL-6, IL-10, cortisol and TSH levels in advanced carcinoma cases. These data indicated that cortisol, IL-6 and neopterin values of cancer patients were influenced by the tumor presence and progression.

Gut bacteria play an important role in the digestion of food, immune activation, and regulation of entero-endocrine signaling pathways, but also communicate with the central nervous system (CNS) through the production of specific metabolic compounds, e.g., bile acids, short-chain fatty acids (SCFAs), glutamate (Glu), γ-aminobutyric acid (GABA), dopamine (DA), norepinephrine (NE), serotonin (5-HT) and histamine. Afferent vagus nerve (VN) fibers that transport signals from the gastro-intestinal tract (GIT) and gut microbiota to the brain are also linked to receptors in the esophagus, liver, and pancreas. In response to these stimuli, the brain sends signals back to entero-epithelial cells via efferent VN fibers. Fibers of the VN are not in direct contact with the gut wall or intestinal microbiota. Instead, signals reach the gut microbiota via 100 to 500 million neurons from the enteric nervous system (ENS) in the submucosa and myenteric plexus of the gut wall. The modulation, development, and renewal of ENS neurons are controlled by gut microbiota, especially those with the ability to produce and metabolize hormones. Signals generated by the hypothalamus reach the pituitary and adrenal glands and communicate with entero-epithelial cells via the hypothalamic pituitary adrenal axis (HPA). SCFAs produced by gut bacteria adhere to free fatty acid receptors (FFARs) on the surface of intestinal epithelial cells (IECs) and interact with neurons or enter the circulatory system. Gut bacteria alter the synthesis and degradation of neurotransmitters. This review focuses on the effect that gut bacteria have on the production of neurotransmitters and vice versa.

En plus d'être une source de nutriments essentiels à notre organisme, les protéines alimentaires participent à la régulation de l'homéostasie énergétique. Dans un contexte épidémique d'obésité, de surconsommation alimentaire, et donc de raréfaction des ressources, la caractérisation du rôle des protéines sur la santé devient cruciale. De manière générale, les protéines sont connues pour réduire la prise alimentaire, en stimulant la satiété, et améliorer l'homéostasie du glucose, mais très peu d'études se sont intéressées à comparer les effets de l'origine protéique sur ces phénomènes. L'objectif de cette thèse est de comparer des protéines, de sources alimentaires différentes, sur certains mécanismes impliqués dans la régulation périphérique de la prise alimentaire. Ainsi des protéines d'origines animales ou végétales ont été sélectionnées : l'hémoglobine bovine, les caséines, l'ovalbumine, le lactosérum, la gélatine de poisson, les protéines de pois et de gluten. Ces protéines ont d'abord été étudiées et comparées in vivo chez le rat. Une première étude utilisant des cages métaboliques a permis de déterminer l'effet sur la prise alimentaire à court terme, la dépense énergétique, le coefficient d'échange gazeux, et l'activité locomotrice. Une seconde étude a permis d'étudier l'effet des protéines sur la régulation de l'absorption intestinale du glucose, sur la modulation de la sécrétion des hormones intestinales et sur l'inhibition de l'activité de la DPP-IV (Dipeptidyl peptidase IV) et une troisième étude, a été réaliser pour déterminer l'effet des protéines sur l'homéostasie glucidique. En parallèle, des études fonctionnelles complémentaires ont été menées ex vivo sur des parties d'intestin de rat et in vitro sur différents modèles cellulaires intestinaux. Les protéines ont alors été digérées à l'aide d'un protocole de digestion gastrointestinal statique adapté à la digestion de protéines seules. Les résultats obtenus mettent globalement en évidence un effet de la source protéique sur l'homéostasie énergétique via des actions différentes sur les marqueurs étudiés. Ce travail met également en évidence, pour la première fois, qu'un apport aigu en protéines pourrait améliorer la tolérance au glucose en inhibant son absorption par l'intestin. En effet, les digestats protéiques ont été capables de diminuer l'absorption intestinale du glucose in vitro et ex vivo et l'ingestion aiguë de caséines et de gélatine de poisson a permis d'améliorer la tolérance au glucose chez le rat sans effet significatif sur la sécrétion d'insuline. L'ensemble de ces études, ont permis de mettre en évidence l'importance des protéines dans les mécanismes de régulation de l'homéostasie énergétique par leurs interactions sur des marqueurs du métabolisme glucidique et de la prise alimentaire qui sont tous les deux très étroitement liés. Les protéines, dépendamment de leur origine modulent plus ou moins la sécrétion des hormones satiétogène et pancréatique, l'activité de la DPP-IV et l'absorption intestinale du glucose
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

This chapter discusses oncological disorders of the endocrine system, including markers for diagnosis, such as chromogranin A, serum neuron-specific enolase, and pancreatic polypeptide (PP). It also describes imaging techniques such as CT and endoscopy, which are matched to neuroendocrine tumour (NET) type. The chapter outlines pathogenesis, symptoms, and management options for NETs such as gastro-entero-pancreatic tumours, insulinomas, gastinomas, glucagonomas, vasoactive intestinal polypeptide (VIP)-secreting tumours or ‘VIPomas’, and somatostatinomas. Ectopic hormone production is described along with disorders such as syndrome of inappropriate anti-diuretic hormone secretion (SIADH), parathyroid hormone-related protein (PTHrP) tumours, ectopic adrenocorticotropic hormone tumours, and human chorionic gonadotrophin (hCG) tumours, as well as their pathophysiology and respective medical management strategies. The chapter details endocrine function following chemotherapy and radiotherapy, listing associated anatomical structures and the biochemical effects of such treatments.

Abstract CCK is a classical gastro-intestinal hormone produced by discrete endocrine cells of the upper small intestine. The first biological actions of CCK to be identified were its ability to stimulate gall bladder contraction and pancreatic exocrine secretion. Other actions of CCK that were subsequently noted by injection of the hormone into animals included effects on gastric emptying, bowel motility, and food intake. Studies in several species have indicated that administration of CCK inhibits gastric emptying (Debas et al. 1975; Anika 1982; Moran and McHugh 1982; Valenzuela and Defilippi 1981); however, it has been difficult to establish whether these effects were physiological or pharmacological. In some studies, simultaneous measurements of pancreatic secretion (Valenzuela and Defilippi 1981) and gall bladder contraction (Debas et al. 1975) were used to estimate physiological CCK levels. Unfortunately these studies have offered conflicting conclusions regarding the role of CCK in gastric emptying.A major difficulty in establishing the physiological effects of CCK has been the limitation in measuring plasma levels of the hormone. This problem has been circumvented only with the recent development of specific and sensitive assays for CCK (Schlegel et al. 1977; Byrnes et al. 1981; Calam et al. 1982; Schafmayer et al. 1982; Chang and Chey 1983; Himeno et al. 1983; Jansen and Lamers 1983; Liddle et al. 1985; Turkelson et al. 1986). The traditional way to prove that a candidate hormone functions in physiological concentrations has been to measure the circulating hormone concentration simultaneously with its target tissue response, and then to reproduce those blood concentrations by infusion of exogenous hormone and determine the effect on the target tissue. With this approach it has been demonstrated that CCK has several hormonal actions, including delaying the gastric emptying of liquids (Liddle et al. 1986).

Abstract The inhibitory effect on food intake of exogenously administered CCK octapeptide CCK-8, initially noted as a side-effect (Sjödin 1972), was first demonstrated experimentally by Gibbs et al. (1973) (see Chapter 17 of this volume). This observation drew attention to peripheral mechanisms in the control of feeding behaviour, a field which had previously been dominated by studies of the brain, notable hypothalamic regulatory mechanisms of hunger. A drawback in the classical experiments on hunger mechanisms had been that the stimuli which initiate a meal in a food-deprived animal are unknown. The study of the peripheral mechanisms which suppress feeding or induce satiety during a meal offered a new perspective because the stimulus which controls the behaviour (satiety) is known (food) and its site of action is also known: the gastro-intestinal tract, a major endocrine organ in the body (Smith 1982). The secretions of this organ may be involved in satiety because administration of food into stomach transplants devoid of nervous supply elicits satiety in animals (Koopmans 1981) and food intake in hungry rats is reduced after their blood is mixed with that of satiated rats (Davis et al. 1967). Thus it is necessary to study the secretions of the gastro-intestinal tract during ingestion of food, particularly as CCK-8, which is secreted from the duodenum during feeding, has been suggested to be a primary satiety-inducing hormone (see Chapter 17 of this volume). However, the study of CCK-8 in satiety has been hampered by the absence of sensitive assay methods. With the development of such methods (Linden 1989), the role of CCK-8 in food intake and satiety has become accessible to direct study and our recent series of such investigations is discussed below.

A healthy gastro intestinal system is important for poultry to achieve its maximumproduction potential. This paper aims gut health and immunity to improve production in the poultry sector. Genetics, Nutrition and Bio security ate the factors influences the production. Gut consisting of various pH and micro biota throughout is an advantageous feature to prevent infections. Various components like Goblet cells, paneth cells, endocrine cells and absorptive enterocytes, tight junctions, GALT and Mucus play a major role in gut health. Balanced diet with optimum carbohydrates, proteins, amino acids, minerals, vitamins, enzymes, organic acids and good management practices are important for improving production. Alteration in supplementation essential amino acids, Zn, Vit E, Se … viz. are needed according to changes in environment and production state of the bird to develop good immunity. Stress free environment with fine hormonal balance are imperative for maximum output. Exploration of genes involved in resistant to food borne pathogens and research towards bio markers for gut health is the need of the hour. In can be concluded that good gut health and immunity play a key role in production. These can be achieved y maintaining birds with optimum nutrients and stress free environment.