INCREASE IN THE FORMATION AND THE SECRETION OF ACTH IN RATS FOLLOWING ADMINISTRATION OF OESTRADIOLMONOBENZOATE

Studies of the effect of both natural and synthetic oestrogens on the size of the adrenal glands have shown a stimulating influence (del Castillo & Sammartino, 1937, Ellison & Burch, 1936, Ingle, 1941). Large doses of oestrogens have also been shown to decrease the content of cholesterol (Levin, 1945) and ascorbic acid (Skelton et al., 1949) in the adrenal glands. Studies with labelled phosphorus in the rat have shown that oestrogen has a marked effect upon the acid-soluble organic phosphate compounds of the adrenal cortex (Gemzell, 1948). All these changes being similar to that produced by ACTH have been interpreted as a manifestation of increased activity in the adrenal cortex. In hypophysectomized rats oestrogen has none of the above effects on the adrenal glands. Subsequently it seems clear that the presence of the pituitary gland is indispensable for the response of the adrenal cortex to oestrogen stimulation.