STZ糖尿病大鼠心肌短型瘦素受体基因的转录表达及心脏纤维化观察

Expression of Short Isoform of Leptin Receptor mRNA and Observation of Cardiac Fibrosis in Hearts of Streptozotocin-Diabetic Rats

目的 研究瘦素受体在STZ糖尿病大鼠心肌中转录表达及心脏的纤维化情况。方法 用STZ制备糖尿病大鼠模型 ,在病程 12周时测定大鼠血压和心功能后处死 ,取心肌组织和分离、培养心脏成纤维细胞 ,用RT PCR检测长、短型瘦素受体mRNA转录表达 ,PCR产物测序 ,电镜观察心肌的超微结构。血清瘦素、胰岛素放射免疫测定。结果 STZ糖尿病大鼠和对照鼠心肌均可转录表达短型瘦素受体mRNA ,两组之间无显著差别 ,但糖尿病心肌成纤维细胞短型瘦素受体mRNA表达较高 ,伴心功能减退和显著的心脏纤维化病理改变。结论 糖尿病大鼠心脏成纤维细胞短型瘦素受体表达增加与心脏纤维化并存。

Purpose: To observe whether the leptin receptor mRNA is expressed and cardiac fibrosis is present in hearts of Streptozotocin - diabetic rats. Methods: The experiment was done at twelfth week after the onset of diabetes. After blood pressure and cardiac function were mearsured, the rats were sacrificed then cardiac tissue and cultured myocardial fibroblasts were used for RT-PCR to show the expression of leptin receptor mRNA. The ultrastructure of myocardium were examed by electron microscopy. Serum leptin, insulin were assessed by immunoassay. Results: Ob-Ra mRNA was expressed in myocardium of streptozotocin - diabetic and control rats with no significant difference between them (P>0.05), but there was higher expression of leptin receptor mRNA in cultured myocardial fibroblasts of diabetic rat. Distinct cardiac fibrosis was found and compained by the decreased heart function in diabetic rats. Conclusions: The coexistence of cardiac fibrosis and increased expression of Ob-Ra mRNA in myocardial fibroblasts were found in diabetic rats.