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

摘要

Objective; To determine the effects of ethanol on nicotinic acetylcholine receptors (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 IQ50 was (45. 55±3. 62) mmol/L. Ethanol (50 mmoI/L) accelerated the slow decay but did not accelerate the quick decay of nicotine-evoked current (Inic) in SCGs. 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.%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12 h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-70 mV,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.