Extrapituitary Interaction between Pitressin and ACTH.

Abstract

One pressor unit of Pitressin, purified natural arginine vasopressin or synthetic arginine vasopressin is equivalent to 0.1 milliunit of ACTH in adrenal ascorbic acid depleting activity in the 24-hour hypophysectomized rat. Pitressin potentiates adrenal ascorbic acid depletion in the 24-hour hypophysectomized rat. Pitressin depletes adrenal ascorbic acid in the rat with a lesion in the median eminence area of the hypothalamus, but only part of this effect can be explained by a direct action on the pituitary since Pitressin has a similar though less pronounced action in a lesioned rat which has been decapitated.