INTERRELATIONS BETWEEN HYPOTHALAMIC SOMATOSTATIN AND PROOPIOMELANOCORTIN NEURONS

Somatostatin receptors were visualized by [I-125]-Tyr0-DTrp8-somatosta tin radioautography on 35% of arcuate neurons containing proopiomelano cortin (POMC) mRNA, as identified by in situ hybridization using a [S- 35] labelled riboprobe on 5 mu m-thick consecutive sections, Furthermo re, double immunohistochemical staining revealed contacts of beta-endo rphin or alpha-MSH containing fibres with a majority of somatostatin p erikarya in the anterior hypothalamic periventricular nucleus. Taken t ogether, these data indicate that hypothalamic somatostatin and POMC n eurons are interconnected, The results are discussed in term of intrah ypothalamic control of GH secretion.