糖尿病鼠早期心脏抗氧化能力及心功能改变与脂质过氧化反应的关系

目的:建立大鼠1型糖尿病模型,探讨糖尿病早期心脏抗氧化能力及心功能改变与氧自由基所致脂质过氧化反应的关系。方法:Wistar鼠16只,体重(250±10)g,随机分为对照组(n=8)及糖尿病组(n=8)。糖尿病模型通过尾静脉注射链脲佐菌素(60 mg/kg)制备。成功制备糖尿病模型后4周观察心脏功能、心肌总抗氧化能力及脂质过氧化产物15-F2t-Isoprostane变化及血清总抗氧化浓度。结果:与对照组相比,4周糖尿病鼠血清及心脏15-F2t-Isoprostane浓度无差异,但糖尿病鼠心脏组织在抗氧化剂t-butylhydroperoxide(t-BHP)刺激下,硫代巴比妥酸反应物质(TBARS)产物显著增强,反映心脏抗氧化能力降低,同时伴有心脏射血分数的显著下降(P<0.05)。结论:糖尿病鼠早期心脏抗氧化能力及心功能的减退早于脂质过氧化损伤的增加。

Decrease in Myocardial Antioxidant Capacity and Cardiac Function Precedes Oxidative Stress-Mediated Lipid Peroxidation Damage in Early Stage Diabetic Rats

Objective:To investigate the changes of myocardial antioxidant capacity and its relationship with cardiac function and reactive oxygen species mediated lipid peroxidation production in rats with early stage diabetes.Methods:Sixteen Wistar rats were randomly assigned to non-diabetic control group(n=8) and diabetic group.Diabetes were induced by a single intravenous injection of streptozotocin(60 mg/kg).Four weeks after the establishment of diabetes,cardiac function,myocardial antioxidant capacity and lipid peroxidation product 15-2t-Isoprostane as well as plasma total antioxidant concentration were assessed.Results:As compared to the control group,plasma and cardiac level of 15-F2t-Isoprostane did not increase in the 4 week diabetic rats.However,myocardial antioxidant capacity was decreased in the diabetic rats,which was reflected by the increased production of TBARS(thiobartituric acid reactive substances) when heart tissue was subjected to in vitro challenge to the oxidant t-butylhydroperoxide(P<0.05),accompanied with reduced cardiac ejection fraction(P<0.05 vs control).Conclusion:Decrease in myocardial antioxidant capacity and cardiac function precedes oxidative stress-mediated lipid peroxidation damage in early stage diabetes in rats.