Cardiopulmonary Receptor Control of Skeletal Muscle Circulation and Renin Release in Normotensive and Hypertensive Subjects

Abstract

This article reviews the importance of cardiopulmonary volume receptors in the reflex control of skeletal muscle circulation and renin release in humans with normal and high arterial blood pressure. In normotensive subjects, selective deactivation and stimulation of cardiopulmonary receptors causes, respectively, an increase and a reduction both in forearm vascular resistance and in plasma renin activity. The ability of these receptors to modulate plasma renin activity is physiologically important because (1) the increase in plasma renin levels that occurs during a cardiopulmonary receptor deactivation accounts for most of the rise in plasma renin activity that occurs during assumption of the upright posture, and (2) cardiopulmonary-receptor induced changes in plasma renin activity and plasma angiotensin II exert an important modulation of sympathetic influence on skeletal muscle because forearm reflex sympathetic vasoconstriction is attenuated by administration of a converting enzyme inhibitor. Finally, the cardiopulmonary receptor control of skeletal muscle circulation and renin release is only slightly altered in mild or moderate essential hypertension. However, preliminary data in essential hypertensive subjects with marked cardiac hypertrophy suggest that an impairment of this control develops in more severe hypertensive conditions.