Study of transmembrane La^(3+) movement in rat ventricular myocytes by the patch-clamp technique  

作　　者：YANG Pin, DU Huizhi & XUE ShaowuInstitute of Molecular Science, Shanxi University, Taiyuan 030006, China 

出　　处：《Chinese Science Bulletin》2002年第18期1518-1522,共5页

基　　金：This work was supported by the National Natural Science Foundation of China (Grant No. 29890280).

摘　　要：We have studied transmembrane La3+ movement in rat ventricular myocytes for the first time by using the whole-cell patch-clamp recording mode. La3+ (0.01-5.0 mmol/L) could not bring out inward currents through the L-type calcium channel in rat ventricular myocytes, while it could enter the cells by the same way carried by 1μmo1/L ionomycin. When the outward Na+ concentration gradient is formed, La3+ can enter the cells via Na-Ca exchange, and the exchange currents increase with the increase of external La3+ concentrations. But compared with Na-Ca exchange currents in the same concentration, the former is only 14%-38% of the latter. The patch-clamp experiment indicates that La3+ normally can not enter ventricular myocytes through L-type calcium channel, but it can enter the cells via Na-Ca exchange.We have studied transmembrane La3+ movement in rat ventricular myocytes for the first time by using the whole-cell patch-clamp recording mode. La3+ (0.01-5.0 mmol/L) could not bring out inward currents through the L-type calcium channel in rat ventricular myocytes, while it could enter the cells by the same way carried by 1 μmol/L ionomycin. When the outward Na+ concentration gradient is formed, La3+ can enter the cells via Na-Ca exchange, and the exchange currents increase with the increase of external La3+ concentrations. But compared with Na-Ca exchange currents in the same concentration, the former is only 14%-38% of the latter. The patch-clamp experiment indicates that La3+ normally can not enter ventricular myocytes through L-type calcium channel, but it can enter the cells via Na-Ca exchange.

关 键 词：WHOLE-CELL PATCH-CLAMP recording ventricular MYOCYTE L-TYPE calcium channel Na-Ca exchange La3+ Ca2+. 

分 类 号：Q25[生物学—细胞生物学]