 Recent studies show that EET and 20-HETE have important biological effects, particularly in the vascular system. The investigators studied the effect of eicosanoids on the gravid rat uterus. The results suggest that 20-HETE had an tocolytics effect on gravid uterus. In the previous study, we demonstrated that the enzymes of the pathway of EET were present in human uterine tissues. Moreover, the addition of an inhibitor of degradation of EET had an tocolytic effect on the human myometrium, as the exogenous addition of 8.9, 14,15-EET and 20-HETE. 