Angiotensin-converting enzyme inhibition reverses luteal phase steroid production in oocyte donors

Objective: To determine whether angiotensin-converting enzyme (ACE) inhibition would affect ovarian steroid synthesis in the oocyte donors undergoing controlled ovarian hyperstimulalion (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 standard COH protocol. Follicle aspiration was performed 34 hours after administration of hCG. After the procedure, seven donors were administered the ACE inhibitor, captopril, 6.25 mg orally twice daily for 4 days. The remaining patients served as Main Outcome Measures: Serum E₂, P, plasma prorenin, active renin, and angiotensin II (Ang II). Results: Angiotensin II increased after aspiration in both groups hut was significantly lower in those receiving captopril. Peak P in the captopril group was significantly lower than controls (81.8 ± 27.8 versus 208.5 ± 23.9 ng/mL [conversion factor to SI unit, 3.180]). Peak E₂ 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 II correlated with P. Conclusions: In stimulated cycles, inhibition of Ang II production appears to raise serum E₂ and lower P levels. Angiotensin II, therefore, may have a role in the regulation of ovarian steroid synthesis.