荭草苷对大鼠急性心肌梗死的保护作用及机制研究

目的 探讨荭草苷对急性心肌梗死模型大鼠的保护作用及机制。方法 建立异丙肾上腺素致大鼠急性心肌梗死模型，将大鼠分为正常对照组、模型组、阳性药普萘洛尔组及低、高剂量荭草苷干预组（1.0、2.0 mg/kg）；采用多道生理记录仪采集心电图、血流动力学指标，检测血清中心肌酶、抗氧化物酶的活性，HE染色观察心肌组织病理学改变，ELISA法检测心肌组织环鸟苷酸（cGMP）水平。结果 与模型组比较，预防性ip 2.0 mg/kg荭草苷连续7 d，可降低大鼠心电图ST段高度变化，明显改善大鼠血流动力学指标，降低大鼠血清心肌酶LDH、ALT和AST的水平，减轻心肌梗死大鼠心肌纤维变性坏死及水肿程度，亦可升高大鼠血清中抗氧化酶SOD、GSH-Px活性及心肌组织中cGMP水平。结论 荭草苷对大鼠急性心肌梗死具有明显保护作用，其保护机制可能与增强体内抗氧化酶活性，提高心肌组织cGMP水平和调节NO/cGMP信号通路有关。

Protection of orientin on acute myocardial infarction in rats and study on its mechanism

Objective To investigate the protective effect of orientin (Ori) on acute myocardial infarction (AMI) in rats and study its mechanism. Methods The rat model with AMI was induced by sc injection of isoproterenol. The rats were randomly divided into five groups, such as control, model, Propranolol (positive control), low- and high-dose Ori (1.0 and 2.0 mg/kg) groups. The electrocardiogram (ECG) and hemodynamic parameters were recorded by PowerLab, the activities of cardiac enzymes and anti- oxidant enzymes were determined, histopathological changes of myocardial tissue were measured by HE staining, and the level of cyclic guanosine monophosphate (cGMP) was detected by ELISA. Results Ip injection of Ori (2.0 mg/kg) for 7 d could reduce the ST segment height of ECG, improve the hemodynamic parameters in rats obviously, decrease the serum myocardial enzyme levels, reduce the myocardial fiber degeneration, necrosis, and edema, and increase the superoxide dismutase and glutathione peroxidase activities and the myocardial cGMP level. Conclusion Ori could protect rats against AMI induced by isoproterenol, which may contribute to enhancing the anti-oxidase activities, elevating the cGMP level of myocardial tissue, and regulating the NO/cGMP signal pathway.