KB-R7943 inhibits Na+-dependent Mg2+ efflux in rat ventricular myocytes
KB-R7943 inhibits Na+-dependent Mg2+ efflux in rat ventricular myocytes
复制标题
KB-R7943 抑制大鼠心室肌细胞中 Na 依赖性 Mg2 流出
DOI：
10.1007/s12576-010-0113-z
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Konishi
中科院分区：
文献类型：
--
作者：
Michiko Tashiro;Hana Inoue;M. Konishi
Na+依赖性Mg 2+外流活性进行了研究与荧光Mg 2+指示剂furaptra在各种潜在的拮抗剂已知抑制其他转运蛋白和通道的存在下。在测试的化合物中，Na+/Ca 2+交换抑制剂KB-R7943最有效地抑制Na+/Mg 2+交换，半抑制浓度（IC 50）为21 μM（25°C）和16 μM（35°C）。这些IC 50值比广泛使用的Na+/Mg 2+交换抑制剂丙咪嗪低三到四倍。除了对Na+/Mg 2+交换的抑制作用外，相对高浓度的KB-R7943（25°C时为100 μM，35°C时≥20 μM）与长时间的紫外线照射相结合，导致细胞缩短，这可能是由于化合物的光毒性和僵硬交叉桥的形成。我们的结论是，KB-R7943可能是一个有用的工具，研究细胞Mg 2+稳态，如果小心，以尽量减少其光毒性。
Na+-dependent Mg2+ efflux activity was studied with the fluorescent Mg2+ indicator furaptra in the presence of various potential antagonists known to inhibit other transporters and channels. Among the compounds tested, KB-R7943, an inhibitor of Na+/Ca2+ exchange, most potently inhibited the Na+/Mg2+ exchange with half inhibitory concentrations (IC50) of 21 μM (25°C) and 16 μM (35°C). These IC50 values were a factor of three to four lower than those of imipramine, a widely used inhibitor of Na+/Mg2+ exchange. Apart from the inhibitory effect on Na+/Mg2+ exchange, relatively high concentrations of KB-R7943 (100 μM at 25°C and ≥20 μM at 35°C), in combination with prolonged UV-illumination, caused cell shortening, probably because of the phototoxicity of the compound and the formation of rigor crossbridges. We conclude that KB-R7943 may be a useful tool to study cellular Mg2+ homeostasis if care is taken to minimize its phototoxicity.