Endocrine Abstracts

The CNS and gut derived peptide Neuromedin U (NMU) has been shown to inhibit feeding following intracerebroventricular (ICV) injection. The present study aimed to further explore the hypothalamic actions of NMU. ICV NMU-23 (1nmol), but not truncated NMU-8, significantly inhibited feeding (1h food intake: 3.8 plus/minus 0.4g vs saline 5.4 plus/minus 0.6g, p <0.05). Following micro-injection into 8 hypothalamic areas, NMU-23 potently inhibited feeding in the PVN (1h food int...

Ghrelin, an endogenous growth hormone secretagogue receptor agonist, increases food intake, growth hormone (GH) and adrenocorticotrophic hormone (ACTH) following intracerebroventricular (ICV) and systemic administration. We now show that low dose intraperitoneal (ip) ghrelin (1nmol) stimulates feeding and results in a plasma ghrelin concentration not significantly different to 24-hour fasting levels. Following injection into 8 hypothalamic nuclei, ghrelin (30pmol) potently sti...

The gastrointestinal-derived hormone peptide YY (PYY) is released from intestinal L-cells post-prandially in proportion to calorie intake, and modulates food intake. Peripheral administration of PYY (3-36) reduces food intake and body weight in rodents and suppresses appetite and food intake in humans. PYY(3-36) is hypothesised to inhibit food intake via activation of the auto-inhibitory pre-synaptic neuropeptide Y (NPY) Y2 receptor (Y2R) present on arcua...

Ghrelin, a circulating gastric hormone, stimulates food intake in rodents and humans and hyperphagia, weight gain and adiposity on chronic administration in rodents. Here we investigated the effect of chronic subcutaneous ghrelin on fat volume and distribution using magnetic resonance imaging (MRI). Male Wistar rats were implanted with subcutaneous osmotic mini-pumps delivering saline (S, n=10) or ghrelin 30nmol/24hours (n=18). In order to investigate the hyperphagia-independe...

The melanocortin receptors (MCR), MC3R and MC4R, have established roles in feeding and pituitary function. MC5R mRNA expression has been identified at low levels in the hypothalamus. However, a role for this receptor in appetite and pituitary function remains to be elucidated. We investigated the effects of central administration of an MC5R agonist (3,3,3-triphenylpropionyl-His-D-Phe-Arg-Trp-NH2) on food intake and plasma pituitary hormone levels. We did not observe...

Hypothalamic Cocaine- and Amphetamine-regulated transcript (CART) is regulated by circulating glucocorticoids. In adrenalectomised rodents, CART expression is reduced in the arcuate nucleus. However, CART also modulates the hypothalamo-pituitary-adrenal (HPA) axis. Acute intracerebroventricular injection of CART peptide significantly increases plasma ACTH and corticosterone but the long-term actions of CART are unknown. The aim of these studies was to determine the effect of l...

The hypothalamic peptide, cocaine and amphetamine regulated transcript (CART) was originally reported to act as an anorexigenic peptide. However, we have recently shown that CART injection into the hypothalamic arcuate nucleus (ARC), acutely stimulates food intake. Here, we characterise the role of arcuate nucleus CART in the long term regulation of food intake and brown adipose tissue (BAT) using i) repeated intra-arcuate injection of CART peptide [CART(55-102)] and ii) polye...