Renin release in relation to plasma noradrenaline during supine exercise in cardiac patients

Plasma renin activity in the brachial artery and in the renal vein together with arterial noradrenaline concentration were determined repeatedly during and after 10 min of dynamic exercise in eight cardiac patients. Arterial renin increased slightly during exercise and gradually returned to control level after exercise. Renal vein renin increased markedly during exercise and returned to the resting value immediately after exercise, similarly to the changes in plasma noradrenaline and heart rate. A close temporal relationship between the changes in the renal veno-arterial renin difference, plasma noradrenaline and heart rate strongly suggests that the sympathetic nervous system is a major determinant of renin release in man during exercise.