ANGIOTENSIN-CONVERTING ENZYME-INHIBITION REVERSES LUTEAL-PHASE STEROID-PRODUCTION IN OOCYTE DONORS

Objective: To determine whether angiotensin-converting enzyme (ACE) in hibition would affect ovarian steroid synthesis in the oocyte donors u ndergoing controlled ovarian hyperstimulation (COH). Setting: The IVF program of the University of Southern California. Design: Prospective matched clinical trial. Patients: Twelve oocyte donors were studied in 28 hyperstimulation cycles. Interventions: Donors underwent a standar d COH protocol; Follicle aspiration was performed 34 hours after admin istration of hCG. After the procedure, seven donors were administered the ACE inhibitor, captopril, 6.25 mg orally twice daily for 4 days, T he remaining patients served as controls. Main Outcome Measures: Serum E(2), P, plasma prorenin, active renin, and angiotensin II (Ang II). Results: Angiotensin II increased after aspiration in both groups but was significantly lower in those receiving captopril, Peak P in the ca ptopril group was significantly lower than controls (81.8 +/- 27.8 ver sus 208.5 +/- 23.9 ng/mL [conversion factor to SI unit, 3.180]). Peak E(2) was significantly higher (2,222.4 +/- 875.3 versus 425.6 +/- 490. 4 pg/mL [conversion factor to SI unit, 3.671]). Active renin and Ang I I correlated with P. Conclusions: In stimulated cycles, inhibition of Ang II production appears to raise serum E(2) and lower P levels. Angi otensin II, therefore, may have a role in the regulation of ovarian st eroid synthesis.