Endocrine Abstracts

Ingested protein has a greater satiating effect than other macronutrients. The underlying mechanism is unknown, but it has been shown that protein induces greater increases in anorectic gut hormone levels than carbohydrate or fat. It was hypothesised that these effects could be mediated by specific amino acids comprising the protein. We therefore examined the effects of specific amino acids on food intake and gut hormone release. Fasted male Wistar rats received an oral gavage...

Background: Peptide-YY is synthesised and secreted by specialised cells in the ileum and colon. Levels increase following food intake, having a satiety effect. Baseline and postprandial levels of PYY were found to be lower in obese subjects compared to lean, negatively correlating with the subjects BMI, however obese subjects were sensitive to the anorectic effects of PYY when given exogenous PYY.Hypothesis: We have recently demonstrated that another pra...

Augurin is a putative neuropeptide product of the esophageal cancer-related gene-4. We have previously demonstrated intra-cerebroventricular (ICV) and intra-paraventricular nucleus (iPVN) administration of augurin (71–148) stimulates the hypothalamo-pituitary-adrenal axis in male Wistar rats. This effect was dependent on the release of CRH. Since CRH is known to inhibit feeding, we hypothesised augurin (71–148) would have similar actions. We therefore investigated th...

In the pancreas, PYY is expressed in a subpopulation of non-beta cells in the islets of Langerhans. The role of PYY-expressing cells in the adult pancreas is unknown. We generated a mouse model in which administration of diphtheria toxin (DT) produced specific ablation of PYY-expressing cells in the colon, pancreas and brainstem. Interestingly, DT administration to adult mice resulted in severe hyperglycaemia associated with significant loss of pancreatic insulin and disrupted...

Glucagon is released from α-cells in the pancreatic islets and is best known for its role in glucose homeostasis. Glucagon/GLP-1 receptor co-agonists have recently been shown to improve glucose homeostasis and reduce body weight in diet-induced obese mice. Glucagon receptor agonism increases energy expenditure while the GLP-1 receptor agonism prevents glucagon-induced hyperglycemia. Peripherally administered glucagon is also capable of reducing food intake, and glucagon n...

Laboratory rats are commonly used to study energy homeostasis. To accurately record food intake or energy expenditure it is necessary to house rats individually, which can be stressful for social animals. Environmental enrichment may reduce stress and improve welfare in laboratory rodents. However, the effect of environmental enrichment on food intake and thus experimental outcome in rats is unknown. We aimed to determine the effect of environmental enrichment on food intake, ...

Neuromedin B (NMB) is a highly conserved bombesin-related peptide found in mammals. The mammalian bombesin family of receptors consists of three closely related G protein coupled receptors, BB1, BB2 and BB3. The BB1 receptor subtype has the highest affinity for NMB. NMB mRNA is detected in the CNS and is expressed at relatively high levels in the rat hypothalamus, in particular the medial preoptic area and the arcuate nucleus.<p ...

Nesfatin is an 82 amino acid peptide identified as a novel hypothalamic regulator of feeding. In rodents, central administration of nesfatin acutely inhibits feeding and chronic administration reduces weight gain. Subsequent research has demonstrated nesfatin is involved in the control of puberty in female rats. During puberty i.c.v. administration of nesfatin stimulates release of LH and FSH but has no effect in adult female rats.We investigated the eff...

Pancreatic polypeptide (PP) is a 36 amino acid peptide, secreted from the endocrine pancreas. Previous work has shown that peripheral administration of PP inhibits food intake in rodents and humans. However, PP has a short circulating half-life that limits its use as an anti-obesity agent. Determining the mechanisms involved in the physiological breakdown of PP will allow the rational design of long-acting analogues with greater clinical utility in the treatment of obesity. PP...

Peptide YY (PYY) is a satiety hormone that communicates nutritional status to the central nervous system. PYY is released postprandially from endocrine L-cells in proportion to calories consumed. It is processed to generate the principle bioactive form PYY3–36, which acts on Y2 receptors in feeding centres within the brainstem and hypothalamus to reduce appetite. Chronic intravenous infusion of PYY3–36 induces weight loss in rodents, and obese humans display low plas...