铬对糖尿病大鼠糖、脂代谢及骨骼肌组织基因表达的影响

目的 :　研究铬对糖尿病大鼠糖、脂代谢及骨骼肌组织中相关基因表达的影响。方法 :　Wistar大鼠 3 2只 ,随机分成 3组 :正常对照组、糖尿病对照组、糖尿病补铬组。补铬组每日以2 0 0 μg/kg bw的铬灌胃 ,连续 6 0 d。补铬前后检测空腹血糖、血清胰岛素及血脂 ;采用 m RNA差异显示技术观察各组大鼠之间骨骼肌中基因表达的变化。结果 :　补铬组大鼠血糖水平较实验前明显降低 ;血清总胆固醇、甘油三酯、低密度脂蛋白胆固醇、动脉硬化指数明显低于糖尿病对照组 ,高密度脂蛋白胆固醇高于糖尿病对照组 ;血清胰岛素水平未见明显改善。分离到补铬组与糖尿病对照组之间出现明显差异的 40 0 bp以上的 c DNA片段 1 1条 ,其中在补铬组中高表达 ,糖尿病对照组中低表达或无表达的 c DNA片段 4条 ;在补铬组中低表达或无表达 ,糖尿病对照组中高表达的 c DNA片段 7条。结论 :　铬对糖尿病大鼠糖、脂代谢紊乱具有一定的改善作用 ;铬对骨骼肌组织中某些基因的表达产生了诱导或抑制作用。推测铬对糖尿病大鼠代谢紊乱的调节作用可能与这些基因表达水平的变化有关。

EFFECTS OF CHROMIUM ON BLOOD GLUCOSE AND LIPID METABOLISM AND GENE EXPRESSION OF SKELETAL MUSCLES IN DIABETIC RATS

Objective: To study the effects of chromium on glucose and lipid metabolism and gene expression in diabetic rats.Methods: Male Wistar rats were assigned to three groups:normal control(NC), alloxan-induced diabetic control group(DM), and DM with chromium supplementation group(DM+Cr). Cr 200 μg/(kg bw·d) was supplemented orally for 60 days. At the end of the treatment, the blood glucose, lipid and serum insulin were measured, and the changes in gene expression among three groups were studied by mRNA differential display technique.Results: Blood glucose in DM+Cr group decreased significantly than that before experiment. The levels of serum TG, TC, LDL-C and AI in DM+Cr group were lower than those of DM group, while the serum HDL-C levels were higher. Serum insulin was not improved obviously in DM+Cr group. 11 cDNA fragments larger than 400 bp expressed differences in skeletal muscles between DM+Cr group and DM group and were isolated, 4 of which expressed higher in DM+Cr group, while the rest expressed higher in DM group.Conclusion: Chromium supplementation could partially improve the disorders of glucose and lipid metabolism, and have an impact on some gene expression in diabetic rats, which may contribute to the regulating effects on its disorders of metabolism.