乙醇对豚鼠单个心房肌细胞L-型钙通道的影响

Effects of alcohol on L-type calcium channel of atrial myocytes in guinea pig

目的:采用膜片钳全细胞记录方法,观察乙醇对分离的豚鼠单个心房肌细胞L-型钙电流(ICa.L)的影响。方法:使用酶解方法获得豚鼠单个心房肌细胞,采用全细胞膜片钳记录技术观察不同浓度乙醇急性干预对ICa.L电流-电压曲线、激活曲线、失活曲线的影响。结果:急性乙醇干预下,ICa.L的I-V曲线发生了变化,而失活曲线未发生变化,激活曲线仅在80mmol/L的时候发生了变化。在乙醇浓度≤45mmol/L时可抑制ICa.L,而在≥50mmol/L时可明显增大ICa.L,在45mmol/L-50mmol/L之间这两种作用发生了突然的转换。结论:乙醇对于ICa.L的影响作用基本为非电压依赖性,但具有浓度依赖性,不同浓度的乙醇可对ICa.L产生不同甚至相反的作用,这有助于解释房颤和房扑之间的关系。

AIM： To observe the effect of acute alcohol intervention on atrial myocytic L- type calcium ion channels （ICa L ） in guinea pig by whole - cell patch clamp technique. METHODS ： Guinea pig atrial myocytes were obtained by enzymolysis. Whol- cell patch clamp was used to gain the Ⅰ-Ⅴ curve, availability curve and activity curve of ICa. L with or without different concentrations of alcohol. RESULTS： The Ⅰ-Ⅴ curves of Ica L were changed by alcohol in a concentration -dependent manner. Inhibition occurred when the alcohol concentration was less than 45 mmol/L, while enhancement was observed with a concentration more than 50 mmol/L. A sudden alternation between the two effects was observed with the alternation between the two concentrations. Alcohol concentration higher to 80 mmol/L did not change the Ⅰ-Ⅴ curve. Alcohol did not change the activity curve or availability curve of ICa. L except the former at concentration of 80 mmol/L. CONCLUSION： Alcohol affects ICa. L in a non -voltage -dependent way and a concentration -dependent manner where different concentrations of alcohol make inverse effects. That may help to elucidate the relationship between atrial fibrillation and atrial flutter.