The effects of non-steroidal anti-inflammatory compounds on human myometrial contractility

Objective: To investigate the effects of inhibitors of COX-1 or COX-2 on myometrial prostaglandin synthesis and on spontaneous contractions in human myometrium. Methods: Cultured myometrial cells were incubated with SC 58560 (COX-1 selective inhibitor) or SC 58236 (COX-2 selective inhibitor), and the production of prostaglandins determined by ELISA. Spontaneously contracting strips of isolated gravid human lower segment myometrium were incubated with SC 58236, meloxicam, DFU, or nimesulide (COX-2 selective inhibitors), with SC 58560 (COX-1 selective inhibitor) or indomethacin (non-selective inhibitor). Results: SC 58236 inhibited the production of prostaglandins from myometrial cells, whereas SC 58560 had less effect. Nimesulide (100 μM) and indomethacin (300 μM) completely inhibited myometrial contractions, whereas meloxicam, DFU, SC 58236 and SC 58560 had less effect. Conclusions: There was no relationship between the inhibition of prostaglandin production and the effects of the compounds on contractility. Myometrial prostaglandin synthesis does not seem to be essential for spontaneous contractility.