A comparison of the effects of two angiotensin converting enzyme inhibitors, SQ 14 225 and MK 422 in Na-restricted sheep.

1. The effects of angiotensin converting enzyme inhibition (CEI) using an intravenous infusion of either SQ 14 225 or MK 422 on blood pressure, plasma renin concentration, blood aldosterone concentration and urinary Na excretion, were studied in sodium-restricted sheep. 2. After 7 days of infusion of either drug mean arterial pressure had decreased and plasma renin concentration had increased. 3. Urinary sodium excretion and blood aldosterone concentration were not altered by infusion of either compound. 4. This study confirms a role for angiotensin II in the control of blood pressure in the Na-restricted sheep but suggests that urinary Na excretion in the sheep is not as dependent on angiotensin II as has been reported in other species.