Cyclic mechanical stretching and interleukin-1α synergistically up-regulate prostacyclin secretion in cultured human uterine myometrial cells

Prostacyclin (PGI2), a potent uterine smooth muscle relaxant, is postulated to be a major prostaglandin (PG) secreted from the human myometrium. PGI2metabolite concentrations in the maternal plasma were reported to be elevated during pregnancy, especially during labor. Recently, we developed cultured human myometrial cells from pregnant women and reported that cyclic mechanical stretching mimicking labor increased PGI2secretion from these cells by up-regulating PGI2synthase promoter activities. Since elevation of cervical/vaginal interleukin-1α (IL-1α) concentrations is also a characteristic feature of delivery, and IL-1α is a known stimulator of PGsynthesis, we investigated a possible synergistic effect of cyclic mechanical stretching and IL-1α on PGI2production in cultured human myometrial cells. Treatment with IL-1α (10 ng/ml) significantly augmented (4- to 60-fold) the secretion of PGI2, prostaglandin E2(PGE2), prostaglandin F2α(PGF2α) and thromboxane A2(TXA2) from cultured human myometrial cells obta...