14-脱羟-11,12-二脱氢穿心莲内酯对1型糖尿病大鼠急性心肌缺血的保护作用

Protective effect of 14-dehydroxylation-11, 12-didehydrogenation andrographolide on acute myocardial ischemia in rats with type 1 diabetes

目的观察14-脱羟-11,12-二脱氢穿心莲内酯对1型糖尿病急性心肌缺血大鼠心肌组织的保护作用。方法选取50只SD大鼠分为正常组和实验组,正常组10只大鼠,实验组40只大鼠均一次性腹腔注射1%链脲佐菌素(STZ)55 mg/kg,制造1型糖尿病动物模型,后选取造模成功的30只大鼠随机分为模型组、药物低剂量组、药物高剂量组,每组10只。药物低、高剂量组分别给予14-脱羟-11,12-二脱氢穿心莲内酯100 mg·kg^(-1)·d^(-1)、200 mg·kg^(-1)·d^(-1),正常组和模型组分别腹腔注射等体积的0.9%氯化钠注射液,连续给药14 d。给药结束后24h,除正常组外,各组大鼠均皮下注射异丙肾上腺素(ISO)5 mg/kg,记录注射异丙肾上腺素后大鼠的Ⅱ导心电图,根据ST段(J点)的偏移判断心肌缺血的程度。断尾取血,测空腹血糖;腹主动脉取血,检测生化指标,苏木精-伊红(HE)染色观察大鼠心肌组织的形态变化,蛋白质印迹法检测心肌核因子(NF)-_κBp65的表达,免疫组织化学检测肿瘤坏死因子(TNF)-α的表达量。结果 14-脱羟-11,12-二脱氢穿心莲内酯100 mg·kg^(-1)·d^(-1)、200 mg·kg^(-1)·d^(-1)组均能降低1型糖尿病大鼠急性心肌缺血时的空腹血糖,可降低肌酸激酶(CK)、乳酸脱氢酶(LDH1)(P<0.05),200 mg·kg^(-1)·d^(-1)组能显著改善糖尿病急性心肌缺血大鼠心电图ST段的偏移程度(P<0.01),100 mg·kg^(-1)·d^(-1)组对ST段的偏移改善不明显(P>0.05)。100 mg·kg^(-1)·d^(-1)组、200 mg·kg^(-1)·d^(-1)组均能改善大鼠的心肌组织病理改变,显著减少TNF-α的表达(P<0.05)和NF-_κBp65的表达(P<0.05)。结论 14-脱羟-11,12-二脱氢穿心莲内酯能降低糖尿病急性心肌缺血大鼠心肌组织中NF-_κBp65、TNF-α的表达,改善心肌组织的损伤。

Objective To investigate the protective effect of 14-dehydroxylation-11, 12-didehydrogenation an-drographolide on myocardial tissues in type 1 diabetic rats with acute myocardial ischemia. Methods Fifty SD rats were divided into the normal group and study group. Ten rats in the normal group and 40 rats in the study group were intraperitoneally injected with 55 mg/kg 1%streptozotocin （STZ）, and the animal models with type 1 diabetes were es-tablished. Thirty successfully established rat models were included and randomly divided into the model group, low-dose group and high-dose group （n=10 each）. The low-dose group and high-dose group were administrated with 100 mg·kg-1·d-1 and 200 mg·kg-1·d-114-dehydroxylation-11, 12-didehydrogenation andrographolide, respectively, and the normal group and model group were injected intraperitoneally with equal volume of saline for 14 d. At 24 h after the administration, the rats in each group were subcutaneously injected with 5 mg/kg isoproterenol （ISO）. The Ⅱ-lead electrocardiogram （ECG） of rats after injection of isoproterenol was recorded. The degree of myocardial ischemia was evaluated according to the deviation of ST segment （J point）. The tails were cut for blood collection, and the fasting blood glucose was measured. The abdominal aorta blood was collected to determine the biochemical indicators. The morphological changes of myocardial tissues in rats were determined by HE Staining. The expression of NF-κBp65 in myocardium was determined by Western-blotting, and the expression of TNF-α was measured by immunohistochem-istry. Results In the 100 mg·kg-1·d-1 and 200 mg·kg-1·d-114-dehydroxylation-11, 12-didehydrogenation andro-grapholide groups, the fasting blood glucose, creatine kinase （CK） and lactate dehydrogenase （LDH1） decreased in type 1 diabetic rats with acute myocardial ischemia （P〈0.05）. In the 200 mg·kg-1·d-1 group, the deviation degree of ST segment of ECG in diabetic rats with acute myocardial ischemia was significantly improved （ P〈0.01）. There was no significant improvement on the deviation of ST segment in the 100 mg·kg-1·d-1 group （P〉0.05）. In the 100 mg·kg-1·d-1 and 200 mg·kg-1·d-1 groups, the pathology of myocardial tissues in rats was changed. In the 100 mg·kg-1·d-1 and 200 mg·kg-1·d-1 groups, the expression of TNF-α （P〈0.05） and NF-κBp65 （P〈0.05） significantly decreased. Conclusion 14-dehydroxylation-11, 12-didehydrogenation andrographolide may decrease the expression of NF-κBp65 and TNF-αin myocardial tissues of diabetic rats with acute myocardial ischemia and improve the damage of myocardial tissues.