Effect of angiotensin-converting enzyme inhibitor on renal function in ovarian hyperstimulation syndrome in the rabbit

Objective: To investigate renal function and whether captopril prevents alt erations in the handling of sodium and water in the ovarian hyperstimulatio n syndrome (OHSS) in the rabbit. Design: Experimental study Setting: Physiology laboratory. Animal(s): Six female New Zealand white rabbits were used as controls, and 13 were hyperstimulated with gonadotropins. Intervention(s): Saline or captopril. Main Outcome Measure(s): Renal excretory and hemodynamic variables. Result(s): The 3% extracellular volume expansion in OHSS animals induced a significant elevation in mean arterial pressure by 27%, although increments in natriuresis and diuresis were similar to those observed in controls. Th e OHSS group had impaired pressure-natriuresis sensitivity compared with co ntrols (0.36 +/- 0.07 mu Eq/min/g of Na excreted per mm Hg vs. 1.74 +/- 0.4 5 mu Eq/min/g of Na excreted per mm. Hg; P < .05. Captopril significantly r educed mean arterial pressure (P < .05) and shifted the pressure-natriuresi s response to the left by 0.85 +/- 0.17 mu Eq/min/g of Na excreted per mum Hu (P < .05). Conclusion(s): In OHSS in the rabbit model. pressure-natriuresis sensitivit y is impaired. Angiotensin H may play a significant role in this phenomenon , since angiotensin-converting enzyme inhibition normalized the pressure-na triuresis relationship. (C) 2001 by American Society for Reproductive Medic ine.