Kusaka M, Sperelakis N
Department of Molecular and Cellular Physiology, College of Medicine, University of Cincinnati, OH 45267, USA.
Biochim Biophys Acta. 1996 Jan 12;1278(1):1-4. doi: 10.1016/0005-2736(95)00238-3.
Possible regulation of fast Na+ channels by tyrosine kinase was examined in human uterine smooth muscle cell line, using whole-cell voltage clamp (at a holding potential of - 90 mV). Bath application of genistein, an inhibitor tyrosine kinase, decreased the fast Na+ current (INa(f)) dose-dependently. The maximal inhibition of INa(f) was 98%, and the concentration for half-maximal inhibition (IC50) was 9 microM. The effect of genistein was rapidly reversible. Daidzein, an inactive analog of genistein, had a similar inhibitory effect on INa(f). These results suggest that the fast Na+ channels in uterine sarcoma cells may be directly blocked by genistein and daidzein, i.e., their effect may be independent of tyrosine kinase inhibition.
利用全细胞膜片钳技术（钳制电位为-90mV），在人子宫平滑肌细胞系中研究了酪氨酸激酶对快速钠通道的潜在调节作用。浴槽中加入酪氨酸激酶抑制剂染料木黄酮后，快速钠电流（INa(f)）呈剂量依赖性降低。INa(f)的最大抑制率为98%，半最大抑制浓度（IC50）为9μM。染料木黄酮的作用可迅速逆转。染料木黄酮的无活性类似物大豆苷元对INa(f)也有类似的抑制作用。这些结果表明，子宫肉瘤细胞中的快速钠通道可能被染料木黄酮和大豆苷元直接阻断，即它们的作用可能与酪氨酸激酶抑制无关。
