Ⅰ型、Ⅲ型胶原基因mRNA在Ⅱ型糖尿病大鼠房室结的表达及变化

Expression of type Ⅰ,Ⅲ collagen mRNA in atrioventricular node of type Ⅱ diabetic rats

目的:探讨Ⅱ型糖尿病大鼠房室结内Ⅰ、Ⅲ型间质胶原重塑及胰岛素对其的影响.方法:高糖高脂饮食加小剂量链脲佐菌素腹腔注射制备Ⅱ型糖尿病大鼠模型,并随机分为正常对照组、糖尿病组和胰岛素治疗组,半定量RT-PCR方法检测Ⅰ型、Ⅲ型胶原基因rmRNA在各组房室结的表达及变化.结果:糖尿病组Ⅰ、Ⅲ型胶原纤维在房室结内明显增加,而治疗组较糖尿病组呈显著下降.图像分析结果显示Ⅰ、Ⅲ型胶原表达量为糖尿病组＞治疗组＞对照组.糖尿病组Ⅰ/Ⅲ型胶原比例明显较对照组上升.结论:Ⅱ型糖尿病大鼠房室结16周后出现间质胶原重塑,胶原类型比例失衡;Ⅱ型糖尿病大鼠行胰岛素降低血糖后可不同程度下调房室结间质胶原的沉积,一定程度上逆转胶原类型比例紊乱.

Objective:To investigate interstitial collagen I and Ⅲ remodelling in atrioventricular node and the role of insulin in type Ⅱ diabetes mellitus rat.Methods:The experimental type Ⅱ diabetic rats were induced by injection of streptozotocin and fed with high fat and high glucose food.The rats were divided into three groups:a normal control group(NC group),a diabetes group(DG) and a treated group.Expression of collagen type Ⅰ and Ⅲ mRNA were detected by RT-PCR.Results:Collagen Ⅰ and Ⅲ in the diabetes group were increased greatly but decreased in the treated group.The expression of collagenⅠ and Ⅲ in all three groups were decreased gradually.The ratio of collagen Ⅰ and Ⅲ increased greatly.Conclusion:Remodelling of interstitial collagen began at 16 weeks in the diabetes group and the ratio of two collagens were unbalanced.The interstitial collagen were reduced after the diabetic rats were treated with insulin which could reverse the disorder of collagen ratio.