吡格列酮对心肌梗死大鼠心肌能量代谢及血流动力学的影响

目的: 探讨吡格列酮对心肌梗死后大鼠心肌能量代谢及血流动力学的影响。方法: 采用开胸结扎冠状动脉左前降支建立心肌梗死模型,取术后72 h存活的20只大鼠随机分为手术组(MI组,n=10)和吡格列酮干预组(P组,n=10,吡格列酮3 mg·kg^-1·d ^-1灌胃8周),另设假手术组(SH组,n=10)。分别喂养8周后用Western blotting法测定大鼠心肌组织中过氧化物酶体增殖物激活受体γ(PPARγ)的蛋白表达水平。用生物组织氧耗测量仪测定线粒体氧化呼吸活性,高效液相层析法(HPLC)法测量线粒体内腺苷酸含量;氚标记二磷酸腺苷(-ADP)掺入法检测线粒体膜腺苷酸转运体(ANT)转运活性,经颈动脉插管测定血流动力学参数,并计算心室重塑指标。结果: 与SH组比较,MI组PPARγ的蛋白表达水平明显下调(P<0.01),线粒体内高能磷酸盐含量、呼吸活性和ANT转运活性明显降低(P<0.01),血流动力学指标紊乱(P<0.01); 与MI组比较,吡格列酮8周干预升高PPARγ的蛋白表达水平,改善心梗后心衰大鼠线粒体呼吸活性及ANT转运活性,增加线粒体内高能磷酸盐含量(P<0.01),但血流动力学指标改善不显著。结论: 心肌梗死后心力衰竭过程中,吡格列酮干预活化PPARγ,升高PPARγ蛋白的表达,可改善心力衰竭大鼠心肌能量代谢;但对血流动力学指标改善不显著。

Effects of pioglitazone on myocardial energy metabolism and hemodynamics in rats with myocardial infarction

AIM: To observe the effects of pioglitazone on myocardial energy metabolism and hemodynamics in rats with heart failure after myocardial infarction (MI). METHODS: The model of MI was established by ligation of left anterior descending artery. The 20 surviving rats were randomly divided into MI group (n=10) and pioglitazone intervention group (P group,n=10, pioglitazone 3 mg·kg^-1·d^-1 orally). The sham-operated rats (SH, n=10) served as controls. Hemodynamic parameters were measured. The ratio of left ventricular weight to body weight (LVW/BW) and the ratio of right ventricular weight to body weight (RVW/BW) were calculated after 8-week treatment. The expression of PPARγ was examined by Western blotting. Mitochondrial respiratory function was determined by Clark oxygen electrodes. The size of adenine acid pool (ATP, ADP and AMP) in mitochondria was measured by HPLC. The adenine nucleotide translocator(ANT) activity was detected by the atractyloside-inhibitor stop technique. RESULTS: Compared with SH group, the protein expression of PPARγ was significantly decreased in MI group (P<0.01). The mitochondrial respiratory activity, the transport activity of ANT and the high-energy phosphate content were decreased in MI group (P<0.01), and the hemodynamic parameters were in disorder (P<0.01). Compared with MI group, the protein expression of PPARγ in P group was significantly increased. The mitochondrial respiratory activity, the high-energy phosphate content, the transport activity of ANT were improved (P<0.01). However, the hemodynamic parameters were not significantly changed.CONCLUSION: Pioglitazone increases the protein expression of PPARγ and improves myocardial energy metabolism in the development of heart failure in the rat model of myocardial infarction, but dose not change the hemodynamic parameters significantly.