心跳骤停期间心肌M胆碱受体变化的实验研究

Experimental study in changes of muscarinic acetylcholine receptor during cardiac arrest in an asphyxiated model

目的：揭示心跳骤停（CA）期间M受体的变化规律，为临床心肺复苏（CPR）时适时应用M受体拮抗剂或激动剂提供理论参考。方法：采用窒息致大鼠心跳骤停的动物模型，随机分为正常对照组、手术对照组、窒息10min、20min、30min组等5组，用放射性配基受体结合分析法分别检测心肌M受体最大结合容量（Bmax）和平衡解离常数（K_D值）。结果：窒息10min组的Bmax开始升高（P＞0．05），窒息20min、30min组的Bmax升高已达显著性和极显著性水平（P分别＜0．05和＜0．01）。且窒息30min组的Bmax高于窒息20min组（P＜0．05）。结论：窒息致CA后期（20min后）心肌M受体密度增高，且随心脏停搏时间的延长而逐渐增高，提示此时应用M受体拮抗剂可能有益于CPR。

Aim: To study the changes of muscarinic acetylcholine receptor (MAChR) during cardiac arrest (CA) and to provide the theoretical foundation for using MAChR antagonist or agonist rationally during clinic cardiopulmonary resuscitation (CPR). Methods: 41 Wistar rats were divided into normal control,sham-operated and asphyxiated 10, 20 and 30 minutes groups randomly with an asphyxiated model. Maximum binding capacity (Bmax) and KD values of MAChR in myocardium were detected by using radioligand binding assay. Results: Bmax of MAChR in myocardium was increased after CA and those in asphyxiated 20, 30minutes groups were significantly higher than that in control group (P< 0.05 and P < 0.01 respectively).Bmax of MAChR in asphyxiated 30 minutes group was also markedly higher than that in asphyxiated 20 minutes group. Conclusion: MAChR number in myocardium was increased after CA (after 20 minutes). It suggested that it be possibly beneficial to perform CPR to treat with MAChR antagonist during CA.