The Influence of Normotensive Pregnancy and Pre-Eclampsia on Angiotensin-Converting Enzyme

Abstract

Serum angiotensin-converting enzyme (SACE) levels were determined in normotensive pregnant subjects and patients with pre-eclampsia in the 3rd trimester of pregnancy and 5 days, 3 and 6 mo. after parturition, and also in the 1st and 2nd trimester in the normotensive group. SACE levels were reduced during pregnancy and 5 days after delivery in the normotensive subjects compared with the levels 3 and 6 mo. after delivery and to the nonpregnant control subjects. After correction for plasma volume expansion, SACE was reduced in 1st and 2nd trimester only. In pre-eclampsia both SACE and corrected SACE were significantly lower in 3rd trimester and 5 days after parturition than 3 and 6 mo. after delivery and in non-pregnant control subjects. The reason for the reduced level of SACE in 1st and 2nd trimester during normal pregnancy is not known. The low SACE levels in pre-eclampsia may be a secondary phenomenon due to a decreased placental synthesis without primary importance for the blood pressure regulation.