Endocrine Abstracts

In addition to expression in the arcuate nucleus of the hypothalamus, POMC is also expressed in a group of neurons in the caudal aspect of the nucleus of the solitary tract, the primary site of synapse of vagal afferent fibers. To test the hypothesis that the brainstem POMC neurons may be involved in satiety signaling, we assessed whether genetic or pharmacological blockade of MC4-R could attenuate the ability of CCK to inhibit food intake. CCK-8s was administered to female C5...

The hypothalamic melanocortin system consists of an endogenous antagonist, agouti related protein (Agrp) and agonist, alpha-melanocyte stimulating hormone (alpha-MSH), which act at the hypothalamic melanocortin 3 and 4 receptors. CNS administration of Agrp increased food intake over a 24-h period. Agrp blocked the reduction in 1-h food intake observed following alpha-MSH administration. This effect occurred independently of whether the antagonist was administered simultaneousl...

With the cloning of the gene encoding pro-opiomelanocortin (POMC) it became apparent that several other peptides distinct from ACTH would be co-secreted from the anterior pituitary into the circulation. This begged the question as to whether these peptides have any biological actions on the adrenal, or to that matter any other tissue. Over the past two decades it has become apparent that the N-terminal fragment known as pro-gamma-MSH plays a role in adrenal physiology.<p c...

In anterior pituitary reaggregate cell culture gamma3-MSH has a mitogenic effect on lactotrophs and augments PRL mRNA levels. Moreover, the peptide increases intracellular free calcium levels ([Ca2+]i) in a subpopulation of cells which is heterogenous with respect to expressed pituitary hormone mRNAs. The effect of gamma3-MSH on ([Ca2+]i is blocked by SHU9119, an MC3- and MC4R antagonist, in only 50% of the responsive cells, suggesting that in half of these cells the mediating...