五甲基槲皮素预处理对大鼠心肌细胞缺氧复氧损伤保护作用的机制研究

目的 探讨五甲基槲皮素（PMQ）预处理对大鼠心肌细胞缺氧/复氧（A/R）损伤的保护作用及其线粒体功能的影响。方法 原代培养SD大鼠乳鼠心肌细胞，经终浓度分别为10，30，100 μmol·L-1 PMQ预处理24 h后，制作A/R损伤，检测培养液中乳酸脱氢酶（LDH） 活性、四唑盐（MTT）比色法检测细胞存活率、流式细胞法检测线粒体膜电位和细胞凋亡情况、线粒体肿胀法检测各组心肌细胞线粒体mPTP开放情况。结果 不同剂量PMQ（10, 30,100 μmol·L-1）预处理24 h后可剂量依赖性的降低LDH活性、增加细胞存活率、减少细胞凋亡（P 〈0.05或P 〈0.01）；30, 100 μmol·L-1 PMQ预处理24 h后，线粒体膜电位更为稳定、mPTP开放减少（P 〈0.05或P 〈0.01）。结论 PMQ预处理24 h后，可产生药理性延迟保护作用，机制与其稳定线粒体膜电位、抑制mPTP开放，进而减少细胞凋亡有关。

Effect of pretreatment with pentamethylquercetin on mitochondrial function in rat cardiomyocyte

AIM： To explore the protective effect of pretreatment with pentamethylquercetin （PMQ） on anoxia/reoxygenation （A/R） injury and mitochondrial function in rat eardiomyocytes. METHODS： Primary neonatal SD rat cardiomyocytes were cultured and pretreated with PMQ in final dose of 10, 30, 100 μmol/L for 24 h, and then underwent A/R injury. After treatment, the activity of LDH was determined by autobiochemistry analysator, cells viability was analyzed by MTT, cell apoptosis and mitoehondrial membrane potential were detected by flow cytometry, opening of mitochondrial permeability transition pore （mPTP） was determined by Ca2＋induced swelling of isolated cardiac mitochondria. RESULTS： Pretreated with different dose of PMQ （10, 30, 100 μmo/L） for 24 h could reduce LDH activity, increase cell viability, decrease cell apoptosis （P 〈 0.05 or P 〈 0.01）in dosedependent manner Moreover, pretreated with 30, 100 μmol/L PMQ for 24 h, mitochondrial membrane potential could be more stable（P〈0.05 or P〈0.01）, and the opening of mPTP could be more lessened（P〈0.05 or P〈0.01）. CONCLUSION： Pretreated with PMQ for 24th could have Pharmacology delay protection, the mechanism involved in stabilizing mitochondrial membrane potential, inhibiting mPTP opening, and reducing cell apoptosis.