缓冲剂HEPES对大鼠离体心脏缺血/再灌注性心律失常及心功能的影响

Effects of HEPES on ischemia/reperfusion arrhythmia and cardiac function of isolated rat hearts

目的:研究缓冲剂HEPES对离体大鼠心脏缺血/再灌注性心律失常及心功能的影响.方法:将34只大鼠随机分为3组:心功能组(n=10),心律失常对照组(n=12)和心律失常HEPES组(n=12).在心功能组,先采用KH液(KrebsHenseleit液)灌注60min作为对照,然后改为台氏液灌注20min,最后再恢复为KH液灌注20min.在心律失常对照组和心律失常HEPES组,分别给予KH液和台氏液灌注,并阻断冠脉左前降支30min,接着再灌注30min.观察心功能指标及心律失常严重程度变化.结果:HEPES可使左室收缩峰压(LVSP),左室发展压(LVDP),左室压变化速率(±LVdp/dtmax)明显降低(P<0.05),使缺血性和再灌注性心律失常积分值明显减少(P<0.05).结论:在采用大鼠离体心脏灌注模型的心功能和心律失常研究中,必须充分考虑HEPES对实验结果可能造成的影响.

AIM: To investigate the effects of 4-(2-hydroxyethyl)-1-piperazine ethanesulphonic acid (HEPES) on ischemia/reperfusion arrhythmia and cardiac function of isolated rat hearts. METHODS: A total of 34 rats were randomly divided into three groups: cardiac function group (n=10), arrhythmia-control group (n=12) and arrhythmia-HEPES group (n=12). In the cardiac function group, following a 60-min equilibration with Krebs-Henseleit solution, the isolated rat hearts were first perfused with Tyrode solution for 20 min and then switched back to Krebs-Henseleit solution for another 20 min. In the arrhythmia-control and arrhythmia-HEPES groups, the hearts were perfused with Krebs-Henseleit and Tyrode solution respectively and the left anterior descending coronary artery was occluded for 30 min, which was followed by a 30 min reperfusion. The severity of arrhythmias and the index of cardiac function were measured. RESULTS: The indices of cardiac function, including LVSP, LVDP and ±LVdp/dt max, decreased significantly when the hearts were perfused with Tyrode solution (P< 0.05). The severity of ischemia- and reperfusion-induced arrhythmias (arrhythmia score) also decreased significantly in the arrhythmia- HEPES group (P<0.05). CONCLUSION: The effects of HEPES on the cardiac function and arrhythmias must be considered when experiments were designed to study the role of agents modifying cardiac function and arrhythmia in isolated rat hearts.