Effects of vasopressin and elimination of corticotropin-releasing hormone-target cells on pro-opiomelanocortin mRNA levels and adrenocorticotropin secretion in ovine anterior pituitary cells

Abstract

Although arginine-vasopressin (AVP) is reported to produce greater ACTH biosynthetic and secretory responses than does corticotropin-releasing hormone (CRH) in sheep anterior pituitary cells, neither factor appears to increase pro-opiomelanocortin (POMC) mRNA levels, as does CRH in the cells of some other species. Since only a fraction of cells that express POMC mRNA may be able to respond to AVP, the aim of this study was to further delineate the regulation of POMC mRNA in ovine anterior pituitary corticotrophs, as a whole and infunctional subpopulations of corticotrophs. We measured the effects of AVP, CRH of activation of protein kinase C by phorbol myristate acetate (PMA) in cultured cel..