KB-R7943对豚鼠心室肌细胞Na^+-Ca^(2+)交换电流的作用  

EFFECT OF KB-R7943 ON Na^+-Ca^(2+) EXCHANGE CURRENT IN GUINEA PIG VENTRICULAR MYOCYTES

作　　者：陆菁[1] 徐向华[1] 王晓良[1] 

机构地区：[1]中国医学科学院,中国协和医科大学药物研究所,北京100050

出　　处：《药学学报》2001年第1期25-28,共4页Acta Pharmaceutica Sinica

基　　金：国家新药基金!资助项目 (96 90 1 0 5 179);国家"973"计划子项目!(G19980 5 110 6 )

摘　　要：目的　观察KB R7943对豚鼠心室肌细胞Na+ Ca2 +交换电流 (INa Ca)的内向电流成分和外向电流成分的影响。方法　采用缺血再灌时胞内Na+超载的细胞模型 ,在同时记录内向、外向电流的双向离子条件下 ,用膜片钳全细胞技术 ,记录INa Ca的电流 电压关系曲线。结果　 10 -6和 10 -5mol·L-1KB R7943 ,在 + 5 0mV时 ,对INa Ca的抑制率分别是 2 9 4%和 6 1 7% ;在 - 80mV时抑制率分别是 2 2 1%和 5 6 9%。结论　KB R7943对豚鼠心室肌细胞INa Ca有抑制作用 ,但对外向成分和内向成分的抑制不具选择性。AIM To study whether KB R7943 has selective inhibitory effect on the inward and outward Na + Ca 2+ exchange current ( I Na Ca ) in guinea pig ventricular myocytes. METHODS Through setting up the model of intracellular Na + overload during myocardial ischemia and reperfusion, the current voltage relationship of I Na Ca was recorded using whole cell patch clamp technique under bi directional ionic conditions. RESULTS Currents were elicited by a declining ramp pulse depolarized immediately from holding potential of -40 mV to +60 mV, then repolarized to -100 mV at a speed of 80 mV·s -1 and returned to the holding potential under bi directional ionic conditions, while the [Na +] was 25 mmol·L -1 in the pipette solution. The currents increased time dependently and voltage dependently which reached from (2 51±0 15) pA·pF -1 to (5 94±0 13) pA·pF -1 at +50 mV and from ( -1 92 ±0 13) pA·pF -1 to ( -3 17 ±0 16) pA·pF -1 at -80 mV ( n =12) after 3 min and there is no significant run down of the current. KB R7943 10 -6 mol·L -1 was found to decrease the current to (4 62±0 05) pA·pF -1 by 29 4% at +50 mV and to ( -2 30 ±0 18) pA·pF -1 by 22 1% at -80 mV ( n =5) after 5 min. While 10 -5 mol·L -1 KB R7943 was shown to decrease the current to (3 13±0 03) pA·pF -1 by 61 7% at +50 mV and to ( -1 62 ±0 03) pA·pF -1 by 56 9% at -80 mV ( n =7). CONCLUSION KB R7943 can block I Na Ca in guinea pig ventricular myocytes. But, it did not show selective inhibition effect on inward and outward currents.

关 键 词：Na^+Ca交换电流 KB-R7943 心室肌细胞 膜片钳 

分 类 号：R542.2[医药卫生—心血管疾病] R331.38[医药卫生—内科学]