ADENOHYPOPHYSIAL GLYCOGENOLYSIS IN RELATION TO ACTH RELEASE INDUCED BY INTRAPITUITARY INJECTION OF A PURIFIED HYPOTHALAMIC CRF

Abstract

Glycogenolysis in the anterior pituitary lobes of the rat was examined following intrapituitary microinjection of varying amounts of a purified pig hypothalamic CRF. The pituitary glycogen showed a significant decrease 20 mins. after direct injection of crude acetic acid extracts of the median eminence or a purified hypothalamic CRF. A greater depletion of the pituitary glycogen was obtained with increasing amount of CRF injected. It was concluded that glycogenolysis is involved in the enhanced ACTH secretion induced by CRF. Furthermore, from the analysis of the correlation between ACTH release and glycogen decrement, it was suggested that secretion of ACTH was biphasic, i.e., glycogenolysis-dependent and-independent.