The Effect of Angiotensin II Infusion on Plasma Catecholamines in the Conscious Rabbit

Abstract

Plasma levels of norepinephrine, epinephrine, and dopamine were measured in conscious, male rabbits. Twenty-minute infusions of 5, 50, and 500 ng/kg/min angiotensin II elevated mean arterial blood pressure by 8 (P < 0.05), 23 (P < 0.01), and 33 mm Hg (P < 0.01), respectively. Plasma catecholamines were unchanged at all levels of angiotensin II infusion except epinephrine which rose from 15 ± 3 to 52 ± 17 pg/ml at 500 ng/kg/min. These data suggest an action of the peptide at the adrenal medulla but offer no evidence of a generalized stimulation of sympathetic discharge by antiotensin II.