Endocrine Abstracts

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...