Pregnant Wistar rats were used to investigate the anti-implantation effect of cyclooxygenase
(COX) inhibitors, indomethacin (nonselective COX-1/COX-2 inhibitor) and celecoxib
(specific COX-2 inhibitor). Indomethacin at doses of 2.5 and 5 mg/kg/day and celecoxib at
doses of 40, 80, and 160 mg/kg/day were orally administered once daily to each group (n=
8) on Days 3–5 of pregnancy (Day 1= sperm detection). Indomethacin and celecoxib at anti-
implantation dosages were further investigated for the effects on changes in endometrial …