ABSTRACT
The effect of indomethacin alone and in combination with some oxytocics [syntocinon and prostaglandin F2] on the pregnant uterus of rabbits was studied in vivo. Recordings were done on one channel of the oscillographic recording apparatus [Model 1980]. The mean amplitude [MA] and the mean number [MN] of the electropotential waves [EPWs] were calculated in 60 second in the record. The intravenous [IV] injection of 0.7 mg/kg indomethacin produced significant decrease in MA and MN of the EPWs. In the combination study, the IV injection of 0.7 mg/kg indomethacin before or after administration of 100 ug/kg prostaglandin F2 [PGF2] was unable to influence the stimulant effect PGF2 on MA and MN of the waves. The other combination therapy showed that the injection of 1.5 IU/kg syntocinon after injection of indomethacin failed to produce its stimulant effect on both MA and Mn of waves. The changes were statistically significant. These observations could advance the postulate that indomethacin is not preferred to be used in the first stage of labor as this may interfere with the effect of both endogenous and exogenous oxytocin. It was also proposed that the inhibitory effect of indomethacin on the pregnant uterus could be overcome by the use of exogenous prostaglandin