EFFECTS OF ACETYLSALICYLIC-ACID (ASPIRIN) AND NAPROXEN SODIUM (NAPROXEN) ON OVULATION, PROSTAGLANDIN, AND PROGESTERONE PRODUCTION IN THE RABBIT

Objective: To determine the effects of acetylsalicylic acid (aspirin) and naproxen sodium (naproxen) on ovulation, ovarian prostaglandins (P G), and P production in the rabbit via in vivo and in vitro studies. D esign: Aspirin and naproxen were administered IV 6.5 and 7 hours, resp ectively after hCG administration to New Zealand White adult female ra bbits. Laparotomy was performed 24 hours after hCG administration. For in vitro experiments, control animals underwent laparotomy 6.5 (aspir in) and 7 hours (naproxen) after hCG administration. The treated anima l received aspirin and naproxen; laparotomy was performed 1 hour later . One ovary was perfused for 6 hours with aspirin or naproxen whereas the contralateral ovary served as a control and was perfused with cont rol medium (M199; GIBCO, Grand Island, New York). Perfusate samples we re collected at 1-hour intervals for PG and P determination. Setting: A conventional laboratory setting. Interventions: In vivo experiments used IV administration of 100 mg/kg aspirin and 10 and 50 mg/kg naprox en. In vitro perfusion was also carried out with 100 mu g/mL aspirin a nd 10 and 50 mu g/mL naproxen added to the perfusate. Main Outcome Mea sures: Ovulatory efficiency (no. of ovulations/no mature follicles) an d ovarian vein PG and P concentration were determined. Results: Ovulat ory efficiency was 88% for control, 41% for in vivo aspirin-treated, a nd 40% (10 mg/kg) and 0% (50 mg/kg) for naproxen-treated rabbits. Aspi rin and naproxen were associated with decreased ovulatory efficiency w hen administered in vitro to both in vivo control and in vivo treated ovaries (control-medium = 70%; control-aspirin = 14%; aspirin-medium = 34%; aspirin-aspirin = 0%; control-naproxen = 25%; naproxen-medium = 38%; naproxen = 0% with 10 mu g/mL, and control-naproxen = 13%; naprox en-medium = 0%; naproxen = 0% with 50 mu g/mL). Prostaglandin Fact was undetectable in the perfusate of those ovaries perfused either with a spirin or naproxen. Ovarian venous concentration of P in the perfusate was similar in all groups. Conclusions: Aspirin and naproxen signific antly reduced ovulatory efficiency and PG production both in vivo and in vitro in hCG-treated rabbits. A critical period of 6.5 and 7 hours after hCG administration was established.