藻蓝蛋白对缺血/再灌注大鼠心肌能量代谢及心功能的影响

Effects of Phycocyanin on Myocardial Energy Metabolism and Cardiac Function in Ischemia/reperfusion Rats

目的:观察藻蓝蛋白对缺血/再灌注大鼠心肌能量代谢及心功能的影响。方法:将30只SD大鼠均分为对照组、缺血组和藻蓝蛋白组,每组10只。除对照组外均建立心肌缺血/再灌注损伤模型。术后待动物清醒后,藻蓝蛋白组灌胃给予藻蓝蛋白治疗2周,对照组、缺血组灌胃给予等体积0.9%氯化钠溶液对照。治疗结束后采用右心室内插入心导管的方法记录心功能并监测Ⅱ导联心电图ST段回落百分比(sumSTR),PR间期及QRS波时限;然后取心脏,采用比色法检测心肌组织Ca^2+/Mg^2+-ATP酶和Na^+/K^+-ATP酶活力,采用BI-2000医学图像分析系统计算各组心肌梗死面积(myocardial infarct size,MIS),比较缺血组和藻蓝蛋白组动物死亡率(mortality rate,MR),藉此分析藻蓝蛋白影响缺血/再灌注大鼠心肌能量代谢及心功能的可能机制。结果:藻蓝蛋白组PR间期和QRS波时限延长,sumSTR回落分布显著优于缺血组(P<0.05),心肌组织Ca^2+/Mg^2+-ATP酶、Na^+/K^+-ATP酶活力、左室射血分数(left ventricular ejection fraction,LVEF)、左室内压力峰值(left ventricular pressure peak,LVSP)和等容收缩期左心室内压力上升最大速率(+dp/dtmax)均升高,MIS减小、等容收缩期左心室内压力下降最大速率(-dp/dtmax)和MR均降低,与缺血组比较差异有统计学意义(P<0.05)。结论:藻蓝蛋白可能通过提高ATP酶活力这一途径来增强心肌能量代谢,从而改善缺血/再灌注大鼠心功能。

Objective To observe the effect of phycocyanin on myocardial energy metabolism and cardiac function in ische⁃mia/reperfusion rats.Methods 30 SD rats were divided into control group,ischemia group and phycocyanin group,with 10 rats in each group.Myocardial ischemia/reperfusion injury models were established except for the control group.After the animals woke up,the rats in the phycocyanin group were given phycocyanin by gavage for 2 weeks,and the rats in the control group and the ischemia group were given an equal volume of 0.9%sodium chloride solution by gavage.At the end of the treatment,the right ventricular catheterization was used to record the cardiac function and monitor the percentage of ST segment depression(sumSTR),PR interval and QRS time limit of lead II ECG;then,the heart was taken and the myocar⁃dial tissue Ca^2+/Mg^2+-ATPase and Na^+/K^+-ATPase activities were measured by colorimetry.The myocardial infarct size(MIS)of each group was calculated by BI-2000 medical image analysis system,and the mortality rate(MR)was com⁃pared between the ischemia group and the phycocyanin group,so as to analyze the possible mechanism of the effect of phy⁃cocyanin on myocardial energy metabolism and cardiac function in ischemia/reperfusion rats.Results In phycocyanin group,the PR interval and QRS time limit were prolonged,and the distribution of sumSTR was significantly better than that of ischemia group(P<0.05).The activities of Ca^2+/Mg^2+-ATPase,Na^+/K^+-ATPase,left ventricular ejection fraction(LVEF)and left ventricular pressure peak(LVSP)and the maximum rate of left ventricular pressure rise during isovolu⁃mic contraction(+dp/dtmax)all increased,MIS decreased,and the maximum rate of left ventricular pressure drop during systole(-dp/dtmax)and MR decreased.The difference was statistically significant compared with ischemia group(P<0.05).Conclusion Phycocyanin may enhance myocardial energy metabolism by increasing ATPase activity,thereby impro⁃ving the cardiac function of ischemia/reperfusion rats.