大黄素对大鼠心肌缺血再灌注损伤的保护作用

The protective effects of emodin preconditioning on ischemia - reperfusion injury in rats

目的观察经过大黄素预处理对大鼠心肌细胞缺血再灌注损伤的保护作用。方法将30只健康sD雄性大鼠随机分为5组，即假手术组（A组，n=6）、心肌缺血再灌注损伤模型组（B组，n=6）、大黄素灌胃预处理组（C组：20mg／kg；D组：40ms／kg；E组：60mg／kg）。除A组外均建立在体大鼠心肌缺血再灌注损伤模型O采用苏木素-伊红（HE）染色法观察心肌细胞病理学改变；反转录一聚合酶链反应（RT．PCR）法测定凋亡相关基因B细胞淋巴瘤／白血病-2（bcl-2）、bcl-2相关X蛋白（bax）、半胱氨酰天冬氨酸特异性蛋白酶（Caspase）-3mRNA表达水平，检测大鼠心肌组织中超氧化物歧化酶（SOD）、丙二醛（MDA）水平的变化。结果与A组比较，B组和各预处理组均出现明确的心肌缺血和心肌梗死区域；各预处理组心肌细胞中bcl-2mRNA表达水平以及SOD、MDA活性均较B组[（1．73±0．21）、（33．15±3．51）U／（mg·pro）]显著提高（P〈0．01），bax和Caspase-3的mRNA丧达水平以及MDA含量较B组[（4．70±0．37）、（4．61±0．52）、（6．87±0．34）nmol／（mg·pro）]明娃降低（P〈0．01）。结论大黄素能够一定程度抑制缺血再灌注损伤诱导的心肌细胞凋亡作用，减轻冉灌注造成的损伤，具有较好的心肌保护作用。

Objective -To investigate the protective effects of emodin on myocardial ischemia - repcrfusion injury （MIRI） in rats. Methods Thirty health male Sprague - Dawley rats were randomly di- vided into five groups ： sham group （ group A）, ischemia - reperfusion group （ group B）, emodin precondi- tioning groups （group C： 20 mg/kg; group D： 40 mg/kg; group E： 60 mg/kg）. The rat MIRI models in vi- vo was established successfully, Hematoxylin -eosinstaining （HE） method was used to identify the pathologit. changes of myocardial tissue. The mRNA expression levels of B cell lymphoma/leukemia - 2 （ bcl - 2 ）, bcl - 2 associated X protein （bax） and cysteinyl aspartate - specific protease - 3 （ Caspase - 3 ） were de- termined by reverse transcription polymerase chain reaction （RT- PCR）. The activities of superoxide dis- mutase （SOD） and the content of malondialdehyde （MDA） were examined. Results Clear myocardial ischemia and myocardial infarction area was found in groups B, C, D and E. As compared with the group B [（1.73 ±0.21）, （33.15 ±3.51） U/（mg.pro） ], the expression of bcl-2 mRNA and the activity of SOl） were increased in groups C, D and E （P 〈 0. 01 ）. The levels of bax and Caspase - 3, and the con- tent of MDA were significantly decreased （P 〈0. 01 ） in groups C, D and E as compared with the group B [（4.70±0.37）, （4.61±0.52）, （6.87±0.34） nmol/（mg.pro）].Conelusion Emodin eaninhibit the apoptosis of myoeardium induced by MIRI to some extent and alleviate the inehemic reperfusion - in- duced injury.