ANGIOTENSIN-CONVERTING ENZYME - SERUM LEVELS DURING NORMAL-PREGNANCY

ACE activity of the serum of 52 normal pregnant women was measured in vitro under conditions of substrate saturation with Hip-His-Leu as substrate. The product His-Leu was measured by fluorimetry after reaction with o-phthaldehyde. ACE activity (nmol/min/ml serum) was 30.6 ± 7.8, 28.8 ± 7.4, and 30.9 ± 8.2 for the first, second, and third trimester of pregnancy, respectively. No statistically significant differences (p>0.05) in ACE activity were detected among the three trimesters of normal pregnancy with either serum volume or serum protein as reference value. These values are within the range reported by Friedland and Silverstein for 51 male and 7 female healthy blood bank donors. The authors conclude that the evolution of normal pregnancy does not significantly modify the levels of ACE in peripheral blood serum.