DIFFERENTIAL REGULATION BY GLUCOCORTICOIDS OF PROOPIOMELANOCORTIN mRNA LEVELS IN THE ANTERIOR AND INTERMEDIATE LOBES OF THE RAT PITUITARY

Abstract

Glucocorticoids negatively regulate de novo synthesis of proopiomelanocortin (POMC) and the steady state POMC mRNA levels in the rat pituitary anterior lobe. The POMC system of the intermediate lobe is far less sensitive to alterations in circulating glucocorticoid levels. Possible mechanisms for this differential regulation of POMC gene expression in the two tissues are discussed.