Effect of captopril on serum angiotensin converting enzyme and blood pressure in hypertensive patients.

ABSTRACT

The effect of chronic captopril therapy on serum angiotensin converting enzyme (ACE) was studied in 30 patients with essential hypertension. Patients were assessed for serum ACE levels serially every week for 4 weeks. Thirty healthy individuals served as controls. The basal serum ACE level among hypertensives (57.4 +/- 37.2 u/l) was found to be significantly higher (p < 0.001) than the controls (33.3 +/- 8.8 u/l). One week after starting captopril therapy, serum ACE levels fell to almost half the basal values (p < 0.001). However, thereafter, it rose to levels higher than the basal level even though the blood pressure remained well controlled. Our study suggests that besides its action on ACE, captopril may lower the blood pressure by other mechanisms as well.