乙醇对培养颈上神经节神经元烟碱型乙酰胆碱受体的影响

Ethanol Inhibits Nicotinc Acetylcholine Receptors in Cultured Superior Cervical Ganglion Neurons

目的:探讨乙醇对培养颈上神经节神经元烟碱型乙酰胆碱受体(nAChRs)的影响。方法:培养新生12h的Wistar大鼠颈上神经节神经元,全细胞膜片钳法记录烟碱诱发电流,观察乙醇对烟碱诱发电流的作用及是否存在浓度依赖性、电压依赖性、使用依赖性,并观察乙醇对颈上神经节神经元nAChRs脱敏的影响。结果:在钳制电位-70mV,乙醇浓度依赖性抑制烟碱诱发电流,IC50(半量抑制率)为(45.55±3.62)mmol/L,可加速nAChRs脱敏,但乙醇对烟碱诱发电流的抑制作用无使用依赖性及电压依赖性。结论:乙醇显著抑制培养的颈上神经节神经元烟碱型nAChRs,其作用位点可能是nAChRs细胞膜外的变构性调节位点。

Objective. To determine the effects of ethanol on nicotinic acetylcholine recep- tors （nAChRs） in cultured primary superior cervical ganglion neurons. Methods： The acute effects of ethanol on nAChRs in cultured primary superior cervical ganglion neurons （SCGs） were examined by whole-cell patch clamp recordings. After the whole-cell configuration formed, drugs diluted to the desired concentrations before using, were applied directly to the single neurons. Results： Holding at --70 mV, inhibition rate of higher concentration of ethanol was larger than that of the lower one. The ICs0 was （45.55＋3.62） mmol/L. Ethanol （50 mmol/L） accelerated the slow decay but did not accelerate the quick decay of nicotine-evoked current （INic） in $CGs. There was no use-dependence and voltage-dependence of ethanol on suppressing INic in SCGs. Conclusion： Ethanol significantly inhibits the whole cell INic in SCGs, probably in a noncompeti- tive inhibition manner in extra-membrane sites.