吡格列酮对糖尿病大鼠心肌肥厚的改善作用

目的探讨噻唑烷二酮(th iazolid ined ione,TZD)类药物吡格列酮对糖尿病大鼠心肌的保护作用。方法应用链脲佐菌素(streptozotoc in,STZ)诱导大鼠糖尿病模型后,吡格列酮组按20 mg.kg-1.d-1混入大鼠饮用水中。大鼠治疗5wk后,检测左心室重量指数(LVI)、心肌细胞面积及横径、心肌组织羟脯氨酸含量和胶原容积分数(CVF);行HE染色观察实质细胞肥大情况,MASSON染色观察胶原纤维增生情况;透射电镜观察心肌超微结构变化。结果吡格列酮组较糖尿病模型组LVI、心肌细胞面积及横径、左心室羟脯氨酸含量及CVF明显降低(P<0.05);光镜下,吡格列酮组较糖尿病模型组心肌实质细胞肥大和间质胶原蛋白增生程度都明显降低;电镜观察,糖尿病模型组心肌细胞明显肥大、间质胶原纤维大量增生、线粒体肿胀,吡格列酮组结构明显改善。结论吡格列酮对早期糖尿病大鼠心肌肥厚有改善作用。

Pioglitazone improves cardiac hypertrophy in diabetic rats

Aim To evaluate the effects of pioglitazone,a thiazolidinedione on the heart of diabetic animals.Methods Streptozotocin(STZ)-induced diabetic rats were divided into two groups: untreated-DM and treated-DM. Pioglitazone(20 mg·kg~(-1)·d~(-1)) was mixed in water fed to the diabetic treated group.After 5 wk,the left ventricle mass index(LVI),cardiomyocytes size and diameters,the content of hydroxyproline and collagen volume fraction(CVF) were measured.The left myocardium sections were made for HE,MASSON straining to observe the level of myocardial cells' hypertrophy and the accumulation of collagen individually and were examined by light microscope.Myocardial ultrastructure was studied by electronic microscope.Results Compared with untreated-DM group,the LVI,cardiomyocytes size and diameters,the content of hydroxyproline and CVF were lower in treated-DM group(P<0.05).By electron microscope,we could observe in untreated-DM group that myocardial cells were enlarged,local myofibrosis and dissolution were in existence;mitochondria were proliferating and swelling.However,the cells in the treated-DM group were ameliorated obviously.Conclusion Pioglitazone can prevent myocardium hypertrophy of diabetic rats,which manifests that pioglitazone can improve the progression of diabetic cardiomyopathy in prediabetic stage of a type 2 diabetic rat.