Plasma renin activity in renal hypertensive rats

Plasma renin activity was estimated in normal and in renal hypertensive rats, in the unanesthetized state, in ether or in urethane anesthesia. Renal hypertension was induced by partially constricting one renal artery without touching the opposite kidney. In the unanesthetized state plasma renin activity in renal hypertensive rats was slightly, though very variably, increased (∼45 percent). Ether anesthesia had no influence on plasma renin activity in either normotensive or hypertensive rats. Urethane anesthesia lowered blood pressure in normotensive controls by 20 mm Hg, and caused a more than threefold increase in plasma renin activity. In renal hypertensive rats urethane depressed blood pressure by 40 mm Hg and induced a more than sixfold increase of plasma renin activity.