Effects of perindopril treatment on plasma and urine of kallikrein activity and the stable metabolite of prostaglandin E2 in patients with essential hypertension.

Eleven male patients with essential hypertension were included in the study. They followed an unrestricted diet and received a single oral daily dose of 4 mg perindopril (ACE inhibitor) for 6 weeks. Plasma renin activity increased significantly and plasma aldosterone decreased significantly after perindopril treatment, suggesting that an effective blockade of angiotensin II formation was accomplished. Both systolic and diastolic blood pressure decreased. Urinary bicycloprostaglandin E2 (an inactive metabolite of prostaglandin E2) increased significantly, while plasma and urinary kallikrein activity decreased significantly after perindopril treatment. The results obtained demonstrated significant changes in prostaglandin E2 and kallikrein activity during ACE inhibition. The contributive role of these humoral factors in the hypotensive effect of perindopril are discussed.