催产素对妊娠末期大鼠蜕膜细胞内游离钙的刺激作用

妊娠末期催产素刺激子宫蜕膜细胞产生与分娩有关的前列腺素,但其作用方式仍未知。本实验分离妊娠19d大鼠蜕膜细胞,测定了催产素作用后蜕膜细胞内游离钙的变化,结果加入0.001～1μmol·L^-1催产素后,蜕膜细胞内[Ca²⁺]i出现瞬息增加,其峰值与催产素浓度呈剂量依赖关系,且此作用有自身钝化现象。说明催产素可能激活妊娠末期大鼠蜕膜细胞内的肌醇磷酯蛋白激酶C系统。给妊娠末期大鼠ip硫酸去氢表雄酮钠盐后分离的蜕膜细胞,催产素作用引起[Ca²⁺]i瞬息增加峰值较对照升高。

OXYTOCIN PROVOKE INTRACELLULAR CALCIUM ION CONCENTRATION IN DISPERSED DECIDUA CELLS OF LATE PREGNANT RATS

It has been postulated that hormonal signal acts upon decidua and ammion totrigger labor via production of PGs.In our experiment the decidua cells of pregnant rats(day 19)were digested and dispersed to test the effect of oxytocin on intracellular calcium ion concentration[Ca²⁺]i which was measured with the fluorecent dye fura-2. Addition of oxytocin 0.001～1μmol·L^-1 to the test system resulted in a dose-dependent transient increase in [Ca²⁺]i which peakedwithin l5s and returned to base line in i2min.Repeated addition of oxytocin 1 μmol·L^-1failed toelicit a repeated response.In the decidua cells of dihydroepiandroterone sulfate-treated pregnant rats,the[Ca²⁺]i peak provoked by oxytocin was significantly higher than in the controls.These resultssuggest that oxytocin may activate the incositol-phospholipid-protein kinase C effector system in deciduacells of prgenant rats.Dihydroepiandrosterone sulfate may influence the action.