机械牵张对钙预适应心肌电生理特性的影响  

Effects of mechanical stretch on electrophysiological characteristics of calcium preconditioning myocardium

作　　者：王志强[1,2] 程龙献[1] 廖玉华[1] 胡恒亮 王嘉陵[4] 盛富强[1] 李星海[5] 

机构地区：[1]华中科技大学同济医学院附属协和医院心血管内科,湖北武汉430022 [2]武汉市妇女儿童医疗保健中心 [3]湖北省黄冈市卫生学校,湖北黄冈438000 [4]华中科技大学同济医学院基础医学院药理系,湖北武汉430030 [5]华中科技大学同济医学院附属协和医院心血管外科,湖北武汉430022

出　　处：《中国病理生理杂志》2005年第7期1265-1269,共5页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.30270559)

摘　　要：目的:研究在模拟缺氧-复氧再灌注条件下机械牵张对钙预适应(CPC)离体豚鼠乳头肌电生理特性的影响。方法:利用细胞内标准玻璃微电极技术,记录并观察一定牵张力(200mg强度)作用下钙预适应乳头肌细胞动作电位(AP)和有效不应期(ERP)的变化。结果:牵张可使单纯缺氧-复氧再灌注(AR)组和CPC组在整个缺氧期除兴奋传导时间(CT)明显延长外,Vmax、RP、APA、APD50、APD90和ERP等参数明显缩短,但对CPC组的影响较小。而牵张可使两组在复氧再灌注期的动作电位的Vmax、RP、APA、APD50和ERP降低,CT和APD90延长,但对CPC组的影响较小。链霉素可抑制机械牵张对CPC组上述参数的影响。结论:在模拟缺氧-复氧再灌注条件下,CPC乳头肌对机械牵张的耐受性增强;链霉素则可抑制牵张对CPC心肌电生理特性的影响。AIM: To investigate the effects of mechanical stretch under simulated anoxia and reoxygenation conditions on action potential (AP) and effective refractory period (ERP) of calcium preconditioning (CPC) in isolated papillary muscles of guinea pig hearts. METHODS: The intracellular standard glass microelectrode technique was used, and effects of stretch (intensity: 200 mg) on AP and ERP were recorded and observed in CPC papillary muscles. RESULTS: After stretching was implied during anoxia, the reductions of Vmax, RP, APA, APD_(50), ERP and APD_(90) in CPC group were less than those in anoxia-reoxygenation (AR) group, and the CT in CPC group was less elongated. Moreover, after the papillary muscles were stretched during reoxygenated reperfusion, the decreases in Vmax, RP, APA, APD_(50) and ERP in CPC group were less than those in AR group, and the CT and APD_(90) in CPC group were less extended. Streptomycin inhibited the effect of stretch on AP and ERP in CPC group. CONCLUSIONS: Under simulated anoxia and reoxygenation conditions, papillary muscles in CPC group may have better tolerance to the same stretch than those in the AR. Furthermore, streptomycin (a blockade of stretch-activated ionic channels) may inhibit the effect of mechanical stretch on action potential changes in CPC papillary muscles.

关 键 词：钙预处理 心肌 动作电位 链霉素 

分 类 号：R541.4[医药卫生—心血管疾病]