Matsubara S, Tamada T, Saito T
Nihon Sanka Fujinka Gakkai Zasshi. 1987 Jul;39(7):1061-8.
In the human amniotic epithelial cell, intracellular Ca++ is known to play an important role in the initiation of parturition. Ca++ATPase is estimated to act on the regulation of the intracellular Ca++ concentration in amniotic epithelial cell. Therefore, to understand the Ca++ metabolism in human term amniotic epithelial cell, ultracytochemical localization of Ca++ATPase activity was investigated. At the same time, the ultracytochemical localization of Ca++ATPase was also compared with other phosphatases to confirm the specificity. Ca++ATPase activity was found to be positive on lateral plasma membrane of amniotic epithelial cell. The activity was strong at a 10mM Ca++ concentration. The activity was also found to be positive on the plasma membrane when 10mM Mg++ was used instead of Ca++. Acid phosphatase activity was positive on the lysosome of the amniotic epithelial cell. The other phosphatase activities appeared negative. These observations suggest that in the amniotic epithelial cell, Ca++ metabolism is active and the Ca++, entering into the cytoplasm, may flow out through the lateral membrane of the amniotic epithelial cell.
在人羊膜上皮细胞中，已知细胞内钙离子（Ca++）在分娩启动过程中发挥重要作用。据估计，Ca++ATP酶作用于调节羊膜上皮细胞内的钙离子浓度。因此，为了解足月人羊膜上皮细胞中的钙离子代谢，对Ca++ATP酶活性进行了超微细胞化学定位研究。同时，还将Ca++ATP酶的超微细胞化学定位与其他磷酸酶进行比较以确认其特异性。发现Ca++ATP酶活性在羊膜上皮细胞的侧质膜上呈阳性。在钙离子浓度为10mM时活性较强。当使用10mM镁离子（Mg++）代替钙离子时，质膜上的活性也呈阳性。酸性磷酸酶活性在羊膜上皮细胞的溶酶体上呈阳性。其他磷酸酶活性呈阴性。这些观察结果表明，在羊膜上皮细胞中，钙离子代谢活跃，进入细胞质的钙离子可能通过羊膜上皮细胞的侧膜流出。
