大鼠实验性心肌梗死后β_2肾上腺素受体动态变化及其拮抗剂对室颤阈值的作用  

Change of β_2 Adrenergic Receptor and Effects of Its Blocker on Ventricular Fibrillation Threshold After Myocardial Infarction

作　　者：杨蕙[1] 伍卫[1] 方昶[1] 张燕[1] 

机构地区：[1]中山大学附属第二医院心内科,广东广州510120

出　　处：《中山大学学报（医学科学版）》2004年第2期122-126,共5页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：广东省教育厅"千百十"优秀人才基金资助项目(Q02032)

摘　　要：【目的】观察心肌梗死后心室肌β2受体mRNA表达水平的动态变化及其拮抗剂对室颤阈值及心室有效不应期的影响。【方法】制作大鼠心肌梗死模型(n=60),随机分为心肌梗死后2、4、8周组,另行假手术为对照组(n=20)。每组再随机分为4小组,分别给予β2受体拮抗剂ICI118,551、β1受体拮抗剂阿替洛尔、β受体拮抗剂普萘洛尔,测定室颤阈值、心室有效不应期。取左室梗死边缘区组织,用RT-PCR方法测定β1、β2受体mRNA表达水平。【结果】心肌梗死后β1受体mRNA表达水平明显下降(P<0.05),β2受体水平无明显变化,β2受体占β受体比例由17%升高至38%(P<0.01);ICI118.551在心肌梗死后4、8周有明显升高室颤阈值作用(P<0.05),且其作用与β2受体占β受体比例呈显著正相关(r=0.99,P<0.05)。【结论】心肌梗死后β2受体在大鼠心脏β受体中所占比例逐渐升高,β2受体拮抗剂提高室颤阈值的作用也逐渐增强,两者呈正相关。To investigate the change of ventricular beta2 adrenergic receptor(AR) mRNA levels and the effects of beta2 adrenergic blocker on ventricular fibrillation threshold(VFT) and ventricular effective refractory period(VERP) after myocardial infarction(MI).①Sixty Wistar rat models with MI were randomly divided into three groups:2,4 and 8 weeks groups after MI.Every group was randomly devided into four subgroups.The subgroups respectively were given beta2 adrenergic blocker ICI 118 551,beta1 adrenergic blocker atenolol,beta adrenergic blocker propranolol separately,VFT and VERP were measured.②Using the reverse transcription PCR, ventricular beta1 AR and beta2 AR mRNA levels in MI boundary region were measured.In comparison with control group,beta1 AR mRNA levels decreased gradually(P< 0.05), whereas the change of beta2 AR had no statistical significance. The ratio between beta2 AR and beta AR increased from 17%to 38%(P< 0.01). ICI 118 551 had the effects of increasing VFT in the 4 and 8 weeks groups after MI(P< 0.05),and the effects had a strong positive correlation with the ratio between beta2 AR and beta AR mRNA levels(r=0.99,P< 0.05).[Conclusion]The ratio between beta2 AR and beta AR increased gradually,and the increasing effect of beta2 adrenergic blocker on ventricular fibrillation threshold is also crescent.The ratio had a positive correlation with the effect.

关 键 词：大鼠 心肌梗死 β2肾上腺素受体拮抗剂 室颤阈值 心脏性猝死 交感神经 

分 类 号：R542.22[医药卫生—心血管疾病]