Alpha and beta adrenergic‐induced renin release in man

Changes in hemodynamic variables and renin release, induced with both alpha and beta adrenergic agonists, were studied in 5 normal men. Saline (0.9% NaCl), methoxamine (1.6 and 5.9 µg/kg/min), and isoproterenol (0.015 and 0.026 µg/kg/min) were infused individually in a random order for 30 min. Methoxamine and isoproterenol caused the predicted directionally opposite cardiovascular changes but caused nearly equal and dose‐related increases in plasma renin activity, as measured by radioimmunoassay. Saline irifusion had no effect. Propranolol (0.125 mg/kg) caused decreases in systolic pressure and heart rate, and a significant decrease in plasma renin activity. Propranolol prevented the renin‐releasing effects of isoproterenol and methoxamine, but only the cardiovascular effects of isoproterenol. It appears that alpha or beta agonists stimulate renin release equally in man and that at least one step in renin release is propranolol‐sensitive. Such sensitivity may be independent of its beta receptor blocking activity.