Prolonged Infusions of Angiotensin II and Norepinephrine and Blood Pressure, Electrolyte Balance, and Aldosterone and Cortisol Secretion in Normal Man and in Cirrhosis with Ascites*

Abstract

Prolonged infusions of angiotensin (up to 11 days) as compared with norepinephrine were carried out in normal subjects and in patients with cirrhosis and ascites under conditions of controlled electrolyte balance. The study revealed that angiotensin fulfills requirements for a trophic hormone for aldosterone because it stimulated aldosterone secretion in mildly pressor dosage; the stimulation was selective because cortisol secretion was not increased; aldosterone stimulation continued for as long as the angiotensin was given. Pressor sensitivity to both angiotensin and norepinephrine was reduced in Na depleted normals and in cirrhosis with ascites. However, studies in normal subjects suggested a specific interaction between angiotensin and the state of Na balance because angiotensin-induced Na retention led to increasing pressor sensitivity followed by "escape".