山楂叶总黄酮对心肌缺血再灌注大鼠心肌线粒体呼吸功能的影响

Effect of Hawthorn Leaves Flavonoids on Mitochondrial Respiratory Function in Rats with Myocardial Ischemia-reperfusion

目的探讨山楂叶总黄酮(HLF)对心肌缺血再灌注(MIR)大鼠心肌线粒体呼吸功能的影响。方法将100只大鼠随机分为假手术组(Sham组)、MIR组、HLF 25 mg/kg组、HLF 50 mg/kg组、HLF 100 mg/kg组,各20只。采用夹闭左冠状动脉前降支30 min方法制备MIR大鼠模型,各组于造模前10 min腹腔注射给药。再灌注2 h后,Clark氧电极法测定心肌线粒体呼吸功能指标[态3呼吸(R3)、态4呼吸(R4)、呼吸控制率(RCR)];比色法检测呼吸酶(还原型辅酶Ⅱ脱氢酶、琥珀酸脱氢酶和细胞色素C氧化酶)活性、三磷酸腺苷(ATP)含量和Na+-K+-ATP酶、Ca2+-ATP酶活性;原子化学发光法测定线粒体Ca2+浓度;透射电子显微镜观察线粒体超微结构;荧光分光光度计检测膜电位(△ψm)、膜通透性转换孔(MPTP)开放度。结果与MIR组比较,HLF 50 mg/kg组、HLF 100 mg/kg组线粒体呼吸功能R3、RCR升高,R4降低,还原型辅酶Ⅱ脱氢酶、琥珀酸脱氢酶、细胞色素C氧化酶活性和ATP含量升高,Na+-K+-ATP酶、Ca2+-ATP酶活性升高,线粒体Ca2+浓度降低;线粒体超微结构病变明显减轻,△ψm升高且MPTP开放度降低,差异均有统计学意义(P<0.05或P<0.01)。结论HLF对MIR大鼠心肌线粒体呼吸功能具有保护作用,其机制可能与抑制线粒体Ca2+超载,维持线粒体膜稳定性有关。

Objective To investigate the effect of Hawthorn Leaves Flavonoids(HLF)on mitochondrial respiratory function in rats with myocardial ischemia-reperfusion(MIR).Methods One hundred rats were randomly divided into Sham group,MIR group,HLF 25 mg/kg group、HLF 50 mg/kg group、HLF 100 mg/kg group,with 20 rats in each group.The MIR rat model was prepared by clamping the anterior descending branch of the left coronary artery for 30 min.The rats in Each group were intraperitoneally injected 10 min before modeling.After reperfusion for 2 h,the myocardial mitochondrial respiratory function index[state 3 respiration(R3),state 4 respiration(R4),respiratory control rate(RCR)]were detected by Clark oxygen electrode method.The activities of respiratory enzymes(NADH dehydrogenase,succinate dehydrogenase and cytochrome C oxidase),adenosine triphosphate(ATP)content,Na+-K+-ATPase and Ca2+-ATPase were detected by colorimetry.Mitochondrial Ca2+concentration was detected by atomic chemiluminescence.The ultrastructure of mitochondria was observed by transmission electron microscope.The membrane potential(△ψm)and mitochondrial permeability transition pore(MPTP)openness was detected by fluorescence spectrophotometer.Results Compared with MIR group,mitochondrial respiratory function R3 and RCR increased,R4 decreased in the HLF 50 mg/kg group,HLF 100 mg/kg group,while activities of NADH dehydrogenase,succinate dehydrogenase,cytochrome C oxidase and the content of ATP were increased(P<0.05 or P<0.01).The activities of Na+-K+-ATPase and Ca2+-ATPase increased,and the mitochondrial Ca2+concentration decreased(P<0.05 or P<0.01).Mitochondrial ultrastructural lesions significantly decreased,△ψm increased and MPTP openness decreased(P<0.05 or P<0.01).Conclusion Hawthorn Leaves Flavonoids could prefect myocardial mitochondrial respiratory function in rats with MIR,its mechanism might be related to inhibiting mitochondrial Ca2+overload and maintaining the stability of mitochondrial membrane.