羧甲基壳聚糖对豚鼠单一心室肌细胞延迟外向钾电流的作用  

EFFECT OF CARBOXYMETHYL CHITOSAN ON DELAYED OUTWARD POTASSIUM CURRENT IN SINGLE VENTRICULAR MYOCYTES OF GUINEA PIG

作　　者：张沈丽[1] 王丽娟[2] 肖庆桓 赵青[1] 李金鸣[1] 

机构地区：[1]中国医科大学药理教研室,沈阳110001 [2]齐齐哈尔医学院药理教研室,齐齐哈尔161042

出　　处：《中国海洋药物》2000年第1期11-13,共3页Chinese Journal of Marine Drugs

摘　　要：研究羧甲基壳聚糖对豚鼠单一心室肌细胞延迟外向钾电流 (IK)的作用 ,从离子通道角度初步探讨其作用机理。应用膜片钳全细胞记录方式 ,设保持电位为 - 50 m V,指令电位为 - 50～ +70 m V,步阶脉冲 1 0 m V,刺激频率 1 Hz,波宽 1 0 0 0 ms,刺激间隔 5s的方波钳制方案。羧甲基壳聚糖能抑制 IK,并呈浓度依赖关系。选择指令电位 +70 m V时给药前后 IK 的变化进行统计 ,当浓度为 0 .1 %时 ,IK由给药前的 1 .1 6± 0 .30 n A减少至药后的 0 .96± 0 .2 7n A(n=4,P<0 .0 1 ) ,其抑制率是 1 7.70± 0 .0 5%。当浓度为 0 .2 %时 ,IK 由给药前的 1 .46±0 .62 n A减少至给药后的 1 .0 6± 0 .49n A(n=4,P<0 .0 1 ) ,抑制率是 2 8.66± 0 .0 6%。其它指令电位下的 IK 的改变也符合此趋势。羧甲基壳聚糖抑制豚鼠单一心室肌细胞延迟外向 K+ 电流。To study the effect of Carboxymethyl chitosan on delayed outward potassium current (I K)in single ventricular myocytes of guinea pig and investigate its antiarrhythmic mechanism from ion channel aspect.Patch clanmp technique with whole-cell configuration.Holding potential was-50mV,commanding potential was-50～+70mV,step pulse+10mV,stimulating frequency 1 Hz,duration 1000 ms and stimulating interval 5 s. Carboxymethyl chitosan inhibited I K in a dose-dependent manner.When holding potential was-50 mV and commanding potential was+70mV,I K reduced from 1.16±0.30nA and 1.46±0.62nA to 0.96±0.27nA(n=4,P<0 01)and 1.06±0.49nA(n=4,P<0 01)respectively after 0.1% and 0.2% Carboxymethyl chitosan were added to the external solution.The inhibitory rate were 17.70±0.05% and 28.66±0.06% respectively. The changes of I K were consistent with this under other commanding potentials.Carboxymethyl chitosan can inhibite I K in single ventricular myocytes of guinea pig.

关 键 词：羧甲基壳聚糖 延迟外向钾电流 膜片钳 

分 类 号：O636.1[理学—高分子化学]