面肌和肢体骨骼肌对罗库溴铵敏感性差异与面神经诱发肌电位监测的研究

A study of the differences in sensitivities to rocuronium between the facial muscles and limb skeletal muscles and facial muscle-evoked myogenic potential monitoring

目的研究面神经支配的肌肉和肢体神经支配的肌肉对罗库溴铵的敏感性是否存在差异,探讨不同肌肉对罗库溴铵的敏感性差异是否与烟碱型乙酰胆碱受体(nicotinic acetylcholine receptor,nAChR)亚基有关,同时探索不同肌肉nAChR的表达差异是否与聚集蛋白(agrin)/低密度脂蛋白受体相关蛋白4(low-density lipoprotein receptor-related protein 4,Lrp4)/肌肉特异性激酶(muscle-specific kinase,MuSK)信号调节通路(即agrin/Lrp4/MuSK通路)和神经调节素1(neuregulin1,NRG1)/表皮生长因子受体(epidermal growth factor receptor,ErbB)信号调节通路(即NRG1/ErbB通路)有关。方法雄性SD大鼠20只取左侧口轮匝肌和腓肠肌分别分为口轮匝肌组(20只)和腓肠肌组(20只),通过离体药效学检测两组肌肉对罗库溴铵的量效曲线,计算药物半数抑制浓度(50%inhibitory concentration,IC50)。通过免疫荧光染色法检测两组肌肉nAChR的α1、β1、δ、ε和γ亚基的表达量。通过RT-PCR和Western blot检测两组肌肉agrin、Lrp4、MuSK、基质金属蛋白酶3(matrix metalloproteinase,MMP3)、NRG1β、ErbB2、ErbB3和ErbB4的mRNA和蛋白表达。结果罗库溴铵对口轮匝肌的IC50大于罗库溴铵对腓肠肌的IC50(P<0.05);口轮匝肌在单位肌肉横截面积上的nAChR亚基密度高于腓肠肌(P<0.05);口轮匝肌NRG1β、ErbB2、ErbB3和ErbB4的mRNA和蛋白表达高于腓肠肌(P<0.05),而agrin、Lrp4、MuSK和MMP3的mRNA和蛋白表达差异没有统计学意义(P>0.05)。结论面神经支配的肌肉对肌肉松弛药的敏感性低于肢体神经支配的肌肉,其机制可能与单位肌肉横截面积上的nAChR亚基密度有关。口轮匝肌中nAChR亚基的高表达与NRG1/ErbB通路有关,而与agrin/Lrp4/MuSK通路无关。

Objective To test the differences in sensitivities to rocuronium between facial nerve-and somatic nerve-innervated muscles,investigate whether the different muscle sensitivities to rocuronium are related to the nicotinic acetylcholine receptor(nAChR)subunits,and explore the relationship between the differences in nAChR expression among these muscles and the agrin/low-density lipoprotein receptor-related protein 4(Lrp4)/muscle-specific kinase(MuSK)and neuregulin1(NRG1)/epidermal growth factor receptor(ErbB)signaling pathways.Methods The left sided orbicularis oris and gastrocnemius were obtained from male Sprague-Dawley rats.Their pharmacodynamic responses to rocuronium were detected in vitro,and the values of 50%inhibitory concentration(IC50)were obtained according to dose-response curves.The levels of nAChRα1,β1,δ,ε,andγsubunits were assessed by immunofluorescence.The mRNA and protein amounts of agrin,Lrp4,MuSK,matrix metalloproteinase(MMP3),NRG1,ErbB2,ErbB3,and ErbB4 were assessed by reverse transcription polymerase chain reaction(RT-PCR)and Western blot.Results The IC50 value of the orbicularis oris to rocuronium was significantly higher than that of the gastrocnemius.The orbicularis oris presented a higher density of nAChR subunits in unit cross-sectional area than the gastrocnemius.The mRNA and protein amounts of NRG1β,ErbB2,ErbB3,and ErbB4 were higher in the orbicularis oris than those in the gastrocnemius.Meanwhile,no differences were observed in the mRNA or protein levels of agrin,Lrp4,MuSK,or MMP3.Conclusions Facial nerve-innervated muscle is less sensitive to skeletal muscular relaxants than somatic nerve-innervated muscle,which may be related to the density of nAChR subunits in unit cross-sectional area.The higher expression of nAChR subunits in the orbicularis oris may be related to the NRG1/ErbB signaling pathway,rather than the agrin/Lrp4/MuSK signaling pathway.