Resistin基因在肥胖易感大鼠与肥胖抗性大鼠脂肪组织中表达差异的研究

Different Expressions of Resistin mRNA in Adipose Tissue between High-fat Diet Induced Obesity-prone and Obesity-resistant Rats

目的探讨高脂饮食诱导下肥胖易感(Obesity鄄prone,OP)大鼠与肥胖抗性(Obesity鄄resistance,OR)大鼠白色脂肪组织中Resistin基因mRNA表达的差异。方法25只雄性SD大鼠,以高脂高能量鼠料饲养2周后,按体重增值大小分组,增重最多9只为OP组,增重最少9只为OR组,余7只为正常对照组(C组),OP、OR大鼠继续饲以高脂高能量鼠料4周,对照组改饲标准鼠料。观察各大鼠体重变化、脂肪组织湿重、血脂、血糖、血清胰岛素等,并采用NorthernBlot技术分析脂肪组织中Resistin基因的mRNA表达水平。结果①高脂高能量鼠料诱导下,OP组大鼠体重、附睾周围及腹膜后脂肪组织湿重明显高于C组,OR组则显著低于C组,但各组间血脂、血糖、血清胰岛素水平并无显著差异(P>0.05);②OP组大鼠附睾周围和腹膜后脂肪组织中ResistinmRNA表达水平均显著高于C组与OR组,OR组则低于C组,且附睾周围脂肪组织中ResistinmRNA表达水平显著高于腹膜后脂肪组织。结论OP与OR大鼠外周脂肪组织存在Resistin基因mRNA表达的差异,其差异与大鼠发生肥胖的易感程度有关。

Objective: To observe the different expressions of resistin mRNA in adipose tissue between obesity-prone rats(OP)and obesity-resistant(OR) rats on a high-fat diet. Methods: After 2 weeks on the high-fat diet(HFD), 25 male Sprague-Dawley rats were separated on the basis of body weight gain into three groups. The 9 rats with the biggest body weight gain were designated as OP group and the 9 rats with the smallest body weight gain were designated as OR group. The remaining 7 rats, which showed intermediate weight gains, were switched back to chow and were designated as chow-fed controls(C group). The OP and OR animals received the HFD for four more weeks; the controls were fed straight rat chow. The body weights were recorded in the time course of model making. The wet weights of epididymal and retroperitoneal fat pad, the serum lipid and lipoproteins, the serum glucose and the serum insulin were measured when rats were killed. The levels of resistin mRNA expression in adipose tissue were detected by Nrthern Blot technique. Results: ①After 6 weeks on the HFD, the OP rats were showed significantly heavier body weights and wet weights of both epididymal and retroperitoneal fat pad than the chow-fed and OR rats. In contrast, the OR rats weighed significantly less than chow-fed controls in both body weight and fat pad throughout the weight-gain period. However, there was no significant difference in the levels of the serum lipid and lipoproteins, the serum glucose, the serum insulin among three groups. ②The OP rats were showed significantly higher expression of resistin mRNA in both epididymal and retroperitoneal adipose tissue than the chow-fed and OR rats. In contrast, the levels of resistin mRNA expression in adipose tissue of OR rats were significantly less than those of chow-fed and OR rats. Also there was significantly higher expression of resistin mRNA in epididymal adipose tissue than in retroperitoneal adipose tissue. Conclusion: Different expressions of resistin mRNA in adipose tissue exist between high-fat diet induced obesity-prone and obesity-resistant rats, which may be related to the different susceptibility to obesity.