【作者】 张林林；

【导师】 李勋；

【作者基本信息】 苏州大学 ， 心血管内科， 2010， 硕士

【摘要】 目的:探讨心梗后大鼠左室心肌组织中NADPH氧化酶的变化及夹竹桃麻素对NADPH氧化酶干预作用的机制。方法:取雄性SD大鼠,通过结扎左冠状动脉前降支建立大鼠心肌梗塞模型,假手术组为无创缝线只穿过前降支而不结扎,将两组再随机分为药物干预组和安慰剂组两个亚组,术后第二天分别给予等体积的夹竹桃麻素溶液(15mg/kg/day)和生理盐水灌胃,共五周。分别于术前和术后第六周行心超检查。术后第六周处死大鼠,取出心脏,用左心室非梗塞区心肌组织制备心肌匀浆液,采用吸收光度法测定非梗塞区心肌组织中O2-浓度和NADPH氧化酶活性,采用RT-PCR法测定心室肌组织中NADPH氧化酶亚单位gp91phoxmRNA的表达水平,并观察心室肌组织中O2-浓度与NADPH氧化酶活性和gp91phoxmRNA表达水平的相关性。结果:1.假手术组大鼠心室肌组织中O2-浓度为(50300±3416)RLU/mg蛋白,心梗组O2-浓度为(83200±7582)RLU/mg蛋白,与假手术组相比有显著统计学差异(P<0.01)。心梗药物干预组O2-浓度为(53300±5517)RLU/mg蛋白,与心梗组相比具有统计学差异(P<0.05),但与假手术组相比无统计学差异(P=0.45)。假手术药物干预组O2-浓度为(47100±2126)RLU/mg蛋白,与假手术组相比无统计学差异(P=0.41)。2.假手术组大鼠心室肌组织中NADPH氧化酶活性为(3.38±0.35)RLU/mg蛋白,心梗组NADPH氧化酶活性为(4.77±0.46)RLU/mg蛋白,与假手术组相比有显著统计学差异(P<0.01)。心梗药物干预组NADPH氧化酶活性为(3.62±0.32)RLU/mg蛋白,与心梗组相比具有统计学差异(P<0.05),但与假手术组相比无统计学差异(P=0.27)。假手术药物干预组NADPH氧化酶活性为(3.19±0.32)RLU/mg蛋白,与假手术组相比无统计学差异(P=0.37)。3.假手术组大鼠心室肌组织中NADPH氧化酶亚单位gp91phoxmRNA表达水平为(0.46±0.07),心梗组gp91phoxmRNA的表达水平为(0.69±0.06),与假手术组相比有显著统计学差异(P<0.01)。心梗药物干预组gp91phoxmRNA的表达水平为(0.49±0.06),与心梗组相比具有统计学差异(P<0.05),与假手术组相比无统计学差异(P=0.54)。假手术药物干预组gp91phoxmRNA表达水平为(0.44±0.03),与假手术组相比无统计学差异(P=0.64)。4.心室肌组织中O2-浓度与NADPH氧化酶活性有显著相关性(R=0.73,P<0.01),与NADPH氧化酶亚单位gp91phoxmRNA表达水平有显著相关性(R=0.80,P<0.01)。结论:1.心梗组大鼠心室肌组织中O2-浓度、NADPH氧化酶活性和gp91phoxmRNA表达水平明显增高,NADPH氧化酶活性和gp91phoxmRNA表达水平与O2-浓度升高水平呈显著相关,表明心梗后NADPH氧化酶系统被激活。2.夹竹桃麻素通过显著抑制NADPH氧化酶活性和gp91phoxmRNA表达减少O2-生成,提示夹竹桃麻素作为NADPPH氧化酶抑制剂可显著减轻心梗后心肌组织氧化应激水平。更多还原

【Abstract】 Objective: To explore the changes of NADPH oxidase in the rat ventricular tissue after myocardial infarction, and the intervention study on the NADPH oxidase with apocynin.Methods: Using male SD rats, MI group was made by ligation of anterior descending coronary artery, the sham group underwent the same procedure without coronary artery ligation, the animals with MI or sham group were assigned randomly to intragastrically receive apocynin (15 mg/kg/day) or saline respectively on the second day after operation for 5 weeks. Echocardiogram were used before the operation and on the 6th week after the operation respectively. On the 6th week after the operation, the rats were killed and the hearts were removed. The concentration of O2- and the activity of NADPH oxidase were measured by the method of absorption photometry, and the expression level of gp91phox mRNA was detected with RT-PCR, and the correlations between the concentration of O2- and the activity of the NADPH oxidase, and the expression level of the gp91phox mRNA were respectively calculated.Results:1. The concentration of O2- in the MI group[(83200±7582)RLU/mg protein] increased significantly compared to the sham group [(50300±3416)RLU/mg protein](P<0.01). The concentration of O2- in the MI+apocynin group[(53300±5517)RLU/mg protein] decreased significantly compared to the MI group(P<0.05). There were no significant differences between the MI+apocynin group, the sham+apocynin group and the sham group (P=0.45, 0.41).2. The activity of NADPH oxidase in the MI group [(4.77±0.46)RLU/mg protein] increased significantly compared to the sham group[(3.38±0.35)RLU/mg protein](P<0.01). The activity of the NADPH oxidase in the MI+apocynin group[(3.62±0.32)RLU/mg protein] decreased significantly compared to the MI group(P<0.05). There were no significant differences between the MI+apocynin group, the sham+apocynin group and the sham group(P= 0.27, 0.37).3. The expression level of gp91phox mRNA in the MI group [0.69±0.06]increased significantly compared to the sham group[0.46±0.07](P<0.01). The expression level of gp91phox mRNA in the MI+apocynin group[0.49±0.06] decreased significantly compared to the MI group(P<0.05). There were no significant differences between the MI+apocynin group, the sham+apocynin group and the sham group(P=0.54, 0.64).4. The concentration of O2- positively correlated to the activity of the NADPH oxidase(R=0.73,P<0.01), and the expression level of the gp91phox mRNA(R=0.80,P<0.01).Conclusions: 1. The concentration of O2-, the activity of the NADPH oxidase and the expression level of gp91phox mRNA in the MI group increase significantly. There are positive correlations between the concentration of O2- and the activity of NADPH oxidase, and between the concentration of O2- and the expression level of gp91phox mRNA. These indicate that the NADPH oxidase system is actived after myocardial infarction.2. The apocynin decreases the production of O2- by inhibiting the activity of NADPH oxidase and the expression level of gp91phox mRNA. This suggests that apocynin as a NADPH oxidase inhibitor could significantly attenuate the level of oxidase stress after myocardial infarction.更多还原