The effect of angiotensin II infusion on plasma catecholamines in the conscious rabbit

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 less than 0.05), 23 (P less than 0.01), and 33 mm Hg (P less than 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 discharge by angiotensin II.