七氟醚麻醉对大鼠海马α7烟碱型乙酰胆碱受体、胆碱酯酶和胆碱乙酰移位酶蛋白含量的影响

Effects of sevoflurane anesthesia on the quantity of alpha 7 nicotinic acetylcholine receptor,cholinesterase, and choline acetyl translocase in the rat hippocampus

目的研究七氟醚麻醉对大鼠海马α7烟碱型乙酰胆碱受体(α7nAchR)、胆碱酯酶(AChE)、胆碱乙酰移位酶(ChaT)蛋白含量的影响。方法健康SD新生大鼠120只,雌雄不拘,1周龄,随机分为五组:空白组、空氧组、七氟醚组(SEV组)、α7nAchR激动剂组(PNU组)和α7nAchR拮抗剂组(MLA组),每组24只。空白组自由喂养;空氧组吸入60%的氧气即运载气体(1 L/min O_2+1 L/min空气)2 h;SEV组吸入3.4%七氟醚+运载气体2 h;PNU组单次腹腔注射α7nAchR激动剂PNU-282987,24 h后吸入3.4%七氟醚+运载气体2 h;MLA组单次腹腔注射α7nAchR拮抗剂甲基牛扁亭,24 h后吸入3.4%七氟醚+运载气体2 h。麻醉清醒后2 h、1周、4周取海马组织,采用Western blot法测定α7nAchR、AChE、ChaT蛋白含量。结果麻醉清醒后2 h SEV组、PNU组、MLA组α7nAchR蛋白含量明显低于空氧组(P<0.05);PNU组、MLA组AChE蛋白含量明显高于空氧组(P<0.05);SEV组、PNU组、MLA组ChaT蛋白含量明显低于空氧组(P<0.05)。麻醉清醒后1周空白组、SEV组、PNU组海马中α7nAchR蛋白含量明显高于空氧组(P<0.05),MLA组α7nAchR蛋白含量明显低于空氧组(P<0.05);空白组、PNU组AChE蛋白含量明显高于空氧组(P<0.05);空白组ChaT蛋白含量明显高于空氧组,SEV组ChaT蛋白含量明显低于空氧组(P<0.05)。麻醉清醒后4周五组AChE蛋白含量差异无统计学意义;SEV组α7nAchR蛋白含量明显高于空白组,PUN组和MLA组明显低于空白组(P<0.05);空白组、SEV组和PNU组ChaT蛋白含量明显低于空氧组,MLA组明显高于空氧组(P<0.05)。结论吸入七氟醚后能抑制ChaT、α7nAChR;对AChE并无直接作用;α7nAChR激动剂能有效缓解吸入七氟醚对α7nAChR、ChaT抑制作用,并在1周左右达到高峰;氧浓度在60%左右能增加α7nAChR蛋白含量,一定程度对抗七氟醚抑制作用。

Objective To investigate the expression of alpha 7 nicotinic acetylcholine receptor(α7 nAchR),cholinesterase(AChE),choline acetyl translocase(ChaT)after sevoflurane anesthesia.Methods A total of 120 healthy Sprague-Dawley rats with both two genders,aged 1 week,were randomly divided into 5 groups:blank group;air/O2 group;sevoflurane group(group SEV);α7 nAchR agonist group(group PUN);α7 nAchR antagonist group(group MLA),24 in each group.Blank group received free feeding,air/O2 group was inhaled 60%oxygen(carrier gas:1 L/min O2+1 L/min air)2 h;group SEV was inhaled 3.4%sevoflurane and carrier gas for 2 h;group PUN and group MLA were injected with PNU-282987 and methyllycaconitine,respectively,after 24 h inhaled of 3.4%sevoflurane and carrier gas for 2 h.After that,hippocampus dissection carried out in 2 h,1 w,4 w,and Western blot method was used to detectα7 nAchR,AChE,ChaT proteins expression.Results Two hours after anesthesia recovery,α7 nAchR in groups SEV,PNU and MLA was significantly lower than that in air/O2 group(P<0.05);AChE in groups PNU and MLA was significantly lower than that in air/O2 group(P<0.05);ChaT in groups SEV,PNU and MLA was significantly lower than that in air/O2 group(P<0.05).One week after anesthesia recovery,α7 nAchR in blank group and groups SEV and PNU was significantly higher than that in air/O2 group(P<0.05),α7 nAchR in group MLA was significantly lower than that in air/O2 group(P<0.05);AChE in blank group and and group PNU was significantly higher than that in air/O2 group(P<0.05),ChaT in blank group was significantly higher than that in air/O2 group(P<0.05),ChaT in group SEV was significantly lower than that in air/O2 group(P<0.05).Four weeks after anesthesia awake,AChE in each group was not statistically significant;α7 nAchR in group SEV was significantly higher than that in blank group(P<0.05),α7 nAchR in group PNU and MLA was significantly lower than that in blank group(P<0.05);ChaT in blank group and group PNU was significantly lower than that in air/O2 group(P<0.05),ChaT in group MLA was significantly higher than that in air/O2 group(P<0.05).Conclusion Sevoflurane inhalation can inhibit ChaT,α7 nAChR,which had no direct effect on AChE;α7 nAChR agonist can effectively helpα7 nAChR and ChaT inhibition inhaled sevoflurane,and reached a peak at about 1 week;oxygen concentration around 60%can increaseα7 nAChR expression quantity,to a certain extent against sevoflurane inhibition.