Failure of angiotensin II to inhibit corticotropin-stimulated cortisol secretion.

In view of the reported inhibitory effect of angiotensin II on cortisol secretion in human subjects, the effect of local angiotensin infusions on steroid secretion maintained by ACTH was examined by using sheep with cervical autotransplanted adrenal glands. During sustained submaximal stimulation by exogenous ACTH (40--80 microunit/min), the addition of local infusions of angiotensin II (1.6--160.0 ng/min) caused increased aldosterone and smaller increments in cortisol secretion in most experients. There was no evidence of inhibition of cortisol secretion by angiotensin. When similar experiments were undertaken during maximum stimulation by ACTH (16.6 mU/min), increments in aldosterone, but not in cortisol secretion, were observed. These studies exclude an acute inhibitory effect of angiotensin on cortisol biosynthesis, at least in ovine adrenal glands, during stimulation by ACTH.