Garner M H, Bahador A, Thi Nguyen B T, Wang R R, Spector A
Department of Ophthalmology, University of California, Irvine 92715.
Exp Eye Res. 1992 Mar;54(3):321-8. doi: 10.1016/0014-4835(92)90044-s.
Na,K-ATPase function was studied in cultured bovine lens epithelial cells under confluent and non-confluent conditions. The affinity of the Na,K-ATPase for the cardiac glycoside, ouabain, differs between the confluent and non-confluent cultures. The confluent cells have a higher affinity for ouabain than do the non-confluent cells. The ouabain affinity of the confluent cells is similar to that for the Na,K-ATPase isolated from the bovine axolemma and the bovine lens cortex. The ouabain affinity of the non-confluent cells is similar to that for the Na,K-ATPase of the renal medulla and bovine lens epithelium. Similar results are not found with confluent and non-confluent MDCK cells. H2O2 treatment of confluent and non-confluent lens epithelial cell cultures has differing effects on the Na,K-ATPase function. In the confluent cell preparations, H2O2 affects K(+)-dependent dephosphorylation of the intermediate phosphoenzyme. In the non-confluent preparations. H2O2 appears to inhibit K(+)-occlusion.
在融合和未融合条件下，对培养的牛晶状体上皮细胞中的钠钾ATP酶功能进行了研究。钠钾ATP酶对强心苷哇巴因的亲和力在融合和未融合培养物之间有所不同。融合细胞对哇巴因的亲和力高于未融合细胞。融合细胞的哇巴因亲和力与从牛轴突膜和牛晶状体皮质分离的钠钾ATP酶相似。未融合细胞的哇巴因亲和力与肾髓质和牛晶状体上皮的钠钾ATP酶相似。融合和未融合的MDCK细胞未发现类似结果。H2O2处理融合和未融合的晶状体上皮细胞培养物对钠钾ATP酶功能有不同影响。在融合细胞制剂中，H2O2影响中间磷酸酶的钾依赖性去磷酸化。在未融合制剂中，H2O2似乎抑制钾的封闭。
