DETERMINATION OF RENIN, ANGIOTENSIN-CONVERTING ENZYME AND ANGIOTENSIN-II LEVELS IN HUMAN PLACENTA, CHORION AND AMNION FROM WOMEN WITH PREGNANCY-INDUCED HYPERTENSION

OBJECTIVE Pregnancy induced hypertension has been shown to be associat ed with a normal or low activity of the maternal circulating renin-ang iotensin system (RAS) but little is known of the local RAS in placenta and fetal membranes. The present study attempts to determine, at full term of human preeclamptic pregnancies, the activity of the chorlopla cental renin-angiotensin system. PATIENTS AND MEASUREMENTS We analysed the concentrations of active renin, prorenin, angiotensin converting enzyme (ACE) and angiotensin II in homogenates of human placenta and f etal membranes from preeclamptic patients at full term pregnancy. The values of renin, ACE and angiotensin II found in the patients with mod erate preeclampsia (gestosis index 0-1) (n = 10) were compared with th ose of normal pregnant women (n = 8). RESULTS Our experiments showed t hat in preeclamptic pregnancies, the chorion membrane contained the hi ghest concentrations of active renin (2905+/-152 pg/g, mean+/-SD), pro renin (21315+/-2849 pg/g) and ACE (1258+/-302 U/g) whereas the placent a had more angiotensin II than the chorion and amnion (741+/-45 vs 456 +/-40 and 428+/-64 pg/g, respectively). In the placenta, as in the fet al membranes, no significant difference was found in the levels of act ive renin, ACE or angiotensin II between hypertensive patients and nor mal subjects but a slightly lower level of chorionic prorenin (P < 0.0 5) was observed in pregnancy induced hypertension. CONCLUSION These fi ndings indicate that in moderate preeclampsia (gestosis index 0-1), th e activity of the renin-angiotensin system in term human placenta and fetal membranes remains essentially normal.