α-硫辛酸对Ⅱ型糖尿病大鼠心肌损伤的保护作用

The protective effects of α-lipoic acid on STZ induced diabetes mellitus myocardial injury in type Ⅱ rats

目的:探讨α-硫辛酸对STZ所致Ⅱ型糖尿病大鼠心肌损伤的保护作用及其机制。方法:SD大鼠随机分为5组:对照组、糖尿病模型组、α-硫辛酸低、中、高剂量组。后4组采用小剂量链尿佐菌素(Streptozocin,STZ)30 mg.kg-1腹腔注射,建立Ⅱ型糖尿病模型。α-硫辛酸低、中、高剂量组分别按15,30,60 mg.kg-1灌胃12周。检测血糖和血脂,心功能状态;HE染色观察大鼠心肌形态变化;免疫组织化学法和Western Blot法测定心肌组织核因子-κB(NF-κB)、细胞间黏附因子-1(ICAM-1)和单核趋化蛋白-1(MCP-1)蛋白表达。结果:与对照组比较,糖尿病组大鼠血糖及三酰甘油(TG)、胆固醇(TC)、低密度脂蛋白(LDL)明显增高(P<0.01),高密度脂蛋白(HDL)明显降低(P<0.01),心肌组织中NF-κB、ICAM-1、MCP-1蛋白表达显著增加(P<0.05);与糖尿病组比较,α-硫辛酸30 mg.kg-1血糖及TG、TC、LDL明显降低(P<0.05),HDL显著提高(P<0.05);LVEDP[(5.6±1.0)mmHg]明显降低(P<0.05),LVSP[(127.6±5.4)mmHg]明显升高(P<0.05);α-硫辛酸30 mg.kg-1组NF-κB、ICAM-1、MCP-1蛋白表达明显减少(P<0.05)。结论:α-硫辛酸对Ⅱ型糖尿病大鼠心肌有保护作用,其机制可能与降糖、降脂、抑制炎症因子有关。

OBJEL-TIVE To explore the protective effects of α-lipoic acid（α-LA）on myocardial tissue in type Ⅱ diabetic ratsinduced by STZ. METItODS SD rats were randomly divided into five groups as follows： the control group, diabetic model group, mLA low, medium and high dose groups. To establish the type Ⅱ diabetes model, small dose of streptozocin 30 mg·kg^-1 ip was used. α-LA low, medium and high dose （ 15, 30, 60 mg·kg^-1 ） was given ig for 12 weeks in the three mLA treat- ment groups. Blood glucose, lipid and heart function states were examined; Protein expressions of myocardial tissue nuclear factor-κB （NF-κB）, intercellular adhesion molecule-l （ICAM-1） and mononuclear chemotactic protein-1 （MCP-1） were also test- ed by immuno-histochemistry and Western blot methods. RESULTS Compared with the control group, the levels of blood glu cose, triglycerides （TG）, cholesterol （TC） and low-density lipoprotein （LDL） in diabetes model rats were increased signifi- cantly （P〈0. 01 ）, high-density lipoprotein （HDL） reduced significantly （P〈0. 01 ）, myocardial tissue NF-κB, ICAM-1, MCP-1 protein expression increased significantly （P〈0. 05）. Compared with diabetes model group, the levels of blood glucose and TG, TC, LDL of α- LA 30 mg·kg-1 group reduced significantly （P〈0. 05）, HDL increased significantly （P〈0. 05） ; LV- EDP （medium 4. 6 ± 1.0） declined significantly （P〈0. 05） and LVSP, ±dp/dtmax （medium 125.6 ± 5.6） elevated （P〈0. 05） by heart function measured. The protein expressions of NF-κB, ICAM-1, MCP 1 ins- LA 30 mg·kg^-1 group were also signifi- cantly reduced （P〈0. 05）. CONCLUSION The protective effects of α-LA was demonstrated on myocardial tissue in type Ⅱ diabetic rats. Its mechanism is partly assciated with lowering blood glucose, lipid and inhibiting inflammation factors involved and so on.