Adrenal hormone responses to cerebroventricular angiotensin II in the sheep.

The effects of intracerebroventricular angiotensin II on plasma aldosterone levels were studied in conscious and anesthetized sheep. Infusion of angiotensin II at 20 ng/min into the lateral cerebral ventricle raised plasma aldosterone levels. Since plasma cortisol increased in parallel with aldosterone, and as the response of both corticosteroids was obliterated by dexamethasone pretreatment, ACTH appeared to mediate the adrenal-stimulating action of angiotensin II. Central infusion of angiotensin II, was without effect on the peripheral renin-angiotensin system or the sympathetic nervous system as gauged by the lack of change in plasma levels of angiotensin II, norepinephrine, and epinephrine.