ACE inhibition in diabetic patients: effect on pressor responsiveness to noradrenaline

The pressor responsiveness to noradrenaline was assessed before and after four weeks of treatment with enalapril (20 mg/day) in eight mild-to-moderate essential hypertensives, in eight normotensive type II diabetics and in eight mild-to-moderate hypertensive type II diabetic patients. The ACE inhibitor interfered to the same extent with the renin-angiotensin system and did not alter noradrenaline kinetics in the three groups of patients, but significantly reduced the arterial responsiveness only in non-diabetic subjects. It is suggested that factors, such as an exaggerated sodium retention, might determine the lack of effect of enalapril in diabetic patients.