Contractile reactivity of human myometrium in isolated non-pregnant uteri

BACKGROUND: Perfusion of the isolated uterus has been shown to be a feasible experimental system for studies of the human endometrium and myometrium. Utilizing our established experimental perfusion model we perfused 20 uteri for 27 h and investigated the contractile reactivity of the myometrium in response to 17 beta-estradiol (E-2) and oxytocin (OT). METHODS: Uteri of group A (n = 4) were stimulated with OT; group B (n = 4) was treated continuously with E-2; group C (n = 4) received both E-2 and OT for 27 h; group D (n = 4) was perfused for 27 h with E-2 with the addition of OT for the last 3 h of the experiment; group E (n = 4) as control group remained without any treatment. The pressure and duration of uterine contractions were recorded during the entire perfusion period using intramural and endoluminal pressure catheters. RESULTS: Compared to the other treatment groups and controls, the most effective myometrial activity was achieved in group D during the OT stimulation period. No relevant myometrial activity was detected in the control group. CONCLUSIONS: Continuous E-2 treatment, with the addition of OT for the last 3 h of the 27 h perfusion period, led to the most pronounced uterotonic effects in the presented experimental condition.