CORTICOSTEROID SECRETION IN THE ADRENAL VENOUS BLOOD OF THE HYPOPHYSECTOMIZED DOG AS AN ASSAY FOR ACTH¹

Abstract

Methods which have been used for the assay of ACTH have been unsatisfactory due to the rather large quantities of the hormone required, poor precision, or dependence upon non-specific end points. The method which is probably most widely used at the present time is that described by Sayers, Sayers, and Woodbury (1948). This procedure which is dependent upon the depletion of ascorbic acid in the hypophysectomized rat appears to have relatively high specificity and requires only very small quantities of ACTH. The mechanism of ascorbic acid depletion is not well understood, however, and its exact relation to corticosteroid secretion is unknown. It has been reported that ascorbic acid depleting factor and also an adrenal weight factor may be separated from various ACTH preparations (Stack-Dunne 1953). The suggestion has also been made that ascorbic acid depleting factor is not always directly related to steroid production (Liddle et al., 1954). The relationship between these various factors,