大鼠老化过程中骨骼肌乙酰胆碱受体含量及功能的改变

Chenges in the contents and function of nicotine acetylcholine reccptors in skeletal musde of rats during aging.

目的 探讨大鼠老化过程中骨骼肌乙酰胆碱受体的含量及功能变化。方法 RT PCR 半定量法检测青年组、中年组、老年早期组和老年晚期组骨骼肌乙酰胆碱受体ε亚单位的表达。比较组间乙酰胆碱(Ach)引起的电流和维库溴铵作用强度的变化。结果 老年早期组和老年晚期组n AChRε亚单位平均辉度比值进行性下降(与青年组比较),其组间比较有显著性差异(P<0.05)。老年早期和老年晚期组Ach激动AChR的EC50 值明显高于青年组、中年组(P<0.05)。维库溴铵对青年组、中年组和老年早期组的n AChR作用强度无显著差异,但对老年晚期组的n AChR作用强度明显增强(P<0.05)。结论 骨骼肌乙酰胆碱受体数量随年龄的增加而进行性地减少,但其对肌松药的作用强度影响较小。老化的骨骼肌乙酰胆碱受体对Ach失敏感,使维库溴铵的作用明显增强。所以在老年人麻醉中,肌松药的使用应谨慎。

Objective Changes in the contents and function of nicotine acetylcholine receptors in skeletal muscle of rats during aging.Methods RT-PCR was performed for the ε subunit of N-AChR mRNA of skeletal muscle in young group, adult group, early stage of aging group, and late stage of aging group muscle. The alterations of Ach-inducing current and vecuronium's effect were compared.Results The expression of ε subunit of N-AChR mRNA was lower in the early and late stage of aging group than that in young and adult group(P< 0.05 ). The EC 50 of the early and late stage of aging group were significantly higher than that of young and adult group (P< 0.05 ). There were not significant difference in vecuronium' effects among the groups of young, adult, and early stage of aging (P> 0.05 ), but which was more potent in late stage of aging group than that in other groups. Conclusion The number of N-AChR is decreased gradually in aging, but which did not affect vecuronium' effects. N-AChR of the aging desensitized Ach, which potentiates vecuronium' effects. So, we should be careful to use neuromuscular relaxant in elder patients.