Sakai Y, Ichikawa S, Yoshida M, Oouchi M, Miyagawa M
Nihon Heikatsukin Gakkai Zasshi. 1982 Nov;18(5):339-45. doi: 10.1540/jsmr1965.18.339.
ATPase activity and Ca2+ uptake were examined in microsomal membrane fractions isolated from guinea pig stomach smooth muscle which had been exposed to phospholipase C (PLC). Basal Mg2+-ATPase, Na+, K+-ATPase and Ca2+, Mg2+-ATP activities were inhibited in a time dependent manner by PLC treatment. There was positive correlations between each of these ATPase activities and total phospholipid content of the microsomal fraction. Phosphotidylcholine restored Ca2+, Mg2+-ATPase activity of the microsomal fraction isolated from the tissue which had been treated with PLC for 30 min but not after 60 min. Ca2+ uptake in the presence of ATP by microsomal fraction from tissue treated with PLC for 60 min was significantly decreased. The results provide a cellular basis for the inhibitory effect of PLC on contractility of stomach smooth muscle.
对从暴露于磷脂酶C（PLC）的豚鼠胃平滑肌中分离出的微粒体膜组分进行了ATP酶活性和Ca2+摄取检测。基础Mg2+-ATP酶、Na+，K+-ATP酶以及Ca2+，Mg2+-ATP活性均受到PLC处理的时间依赖性抑制。这些ATP酶活性中的每一种与微粒体组分的总磷脂含量之间均存在正相关。磷脂酰胆碱可恢复从经PLC处理30分钟而非60分钟的组织中分离出的微粒体组分的Ca2+，Mg2+-ATP酶活性。经PLC处理60分钟的组织的微粒体组分在ATP存在下的Ca2+摄取显著降低。这些结果为PLC对胃平滑肌收缩性的抑制作用提供了细胞基础。
