Peripheral ß-Receptor Responsiveness in Patients With Essential Hypertension

Abstract

Peripheral β-adrenergic receptor sensitivity was characterized in 24 patients with essential hypertension and in 13 agematched normotensive subjects using an isoproterenol hydrochloride bolus dose-response technique. Decreased β-receptor responsiveness to this exogenously administered β-agonist was observed in hypertensive patients; for an equivalent chronotropic effect, higher doses of isoproterenol were required in hypertensive subjects than in normal subjects. Among "normal-renin" hypertensive patients, β-receptor responsiveness was directly related to furosemide-stimulated plasma renin activity (PRA), suggesting that independently stimulated PRA may provide an indirect estimate of endogenous β-receptor sensitivity. Hypertensive patients whose mean arterial pressure fell at least 10 mm Hg after four weeks of treatment with hydrochlorothiazide had even further depression in β-receptor responsiveness, whereas receptor sensitivity was unchanged in patients whose blood pressure was unaffected. Thus, it is unlikely that this decreased receptor responsiveness in patients with untreated essential hypertension is a direct consequence of elevated arterial pressure. (Arch Intern Med139:879-881, 1979)