机械牵张对腺苷预适应心肌电生理特性的影响  

Effects of Mechanical Stretch on Electrophysiological Characteristics of Adenosine Preconditioning Myocardium

作　　者：胡恒亮[1] 程龙献[1] 王志强 苏方成[1] 廖玉华[1] 王嘉陵[3] 

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 [2]湖北省荣军医院心血管内科,武汉430070 [3]华中科技大学同济医学院基础医学院药理学系,武汉430030

出　　处：《华中科技大学学报（医学版）》2007年第1期49-52,共4页Acta Medicinae Universitatis Scientiae et Technologiae Huazhong

基　　金：国家自然科学基金资助项目(No.30270559)

摘　　要：目的研究在模拟缺血-再灌注条件下机械牵张对腺苷预适应(APC)的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200 mg强度牵力作用下APC(在缺血再灌注前先以含6 mg/L腺苷的蒂罗德液灌流5 min)乳头肌细胞动作电位(AP)的变化。结果牵张可使单纯缺血-再灌注(IR)组在整个缺血期动作电位0相最大上升速率(Vmax)、AP幅值(APA)、AP复极达50%的时程(APD50)、静息电位(RP)、AP复极达90%的时程(APD90)等参数明显减小。牵张后IR-S组在复氧再灌注期的Vmax、RP、APA和APD50减小,APD90延长,但APC组牵张前后的各种参数差异无显著性意义。链霉素可抑制机械牵张对APC组上述参数的影响。结论在模拟缺血-再灌注条件下,APC乳头肌对机械牵张的耐受性增强;链霉素可抑制牵张对APC心肌电生理参数的影响,可能具有抗牵张所致心律失常的作用。Objective To investigate the effects of mechanical stretch under simulated ischemia and reperfusion conditions on action potential （AP） of adenosine preconditioning （APC） isolated papillary muscles of guinea pig hearts. Methods The stretch models were made, and the intracellular standard glass microelectrode technique was used to observe the effects of stretch （intensity： 200 mg） on AP in APC （perfusion with Tyrode solution containing 6 mg/L adenosine for 5 min prior to ischemia-reperfusion） isolated papillary muscles. Results The Vmax, APA, APD50 and APD90 in APC group were decreased significantly during ischemic period as compared with those in ischemia-reperfusion group. After stretch, in ischemia-reperfusion group Vmax APA and APD50 were significantly decreased and APD90 prolonged in reoxygenated reperfusion period as compared with those before stretch. However, in APC group there was no significant difference in the changes of various parameters before and after stretch. Streptomycin （200μmol/L） could partly inhibit the effects of mechanical stretch on the above parameters in APC group. Conclusion Under simulated ischemia and reperfusion conditions, the tolerance of APC isolated papillary muscles to mechanical stretch was increased. Streptomycin could inhibit the effect of mechanical stretch on electrophysiological parameters in APC isolated papillary muscles, suggesting its antiarrhythmie effect.

关 键 词：腺苷预适应 心肌 机械牵张 动作电位 

分 类 号：R331.3[医药卫生—人体生理学]