Inhibitory effect of leptin on human uterine contractility in vitro

Objective The purpose of this study was to investigate the effects of leptin on human uterine contractility in vitro. Study design Biopsies of human myometrium were obtained at elective cesarean section (n = 18). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous and oxytocin-induced contractions, were exposed to cumulative additions of leptin in the concentration range of 1 nmol/L to 1 μmol/L. Control strips were run simultaneously. Integrals of contractile activity were measured using the PowerLab hardware unit and Chart v3.6 software. Results Leptin exerted a potent and cumulative inhibitory effect on spontaneous and oxytocin-induced contractions compared to control strips. The mean maximal inhibition values were as follows: 46.794 ± 5.133% (n = 6; P< .001) for spontaneous contractions and 42.323 ± 3.692% (n = 6; P< .001) for oxytocin-induced contractions. There was an apparent reduction in both frequency and amplitude of contractions. Conclusion This physiologic inhibitory effect of leptin on uterine contractility may play a role in the dysfunctional labor process associated with maternal obesity, and the resultant high cesarean section rates.