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

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.Whole-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.