钙对饮食诱导肥胖大鼠抵抗素基因表达的影响

Effect of dietary calcium on expression of resistin gene of obese rats induced by diet

目的 探讨膳食钙对饮食诱导肥胖大鼠白色脂肪组织中抵抗素 (resistin)基因表达的影响。方法 以雄性Wistar大鼠为实验对象 ,用高脂饮食诱导大鼠肥胖模型。将肥胖大鼠按体重随机分为 4组 :A组为基础饲料组 ,B组为高脂低钙组 (含 0 2 5 %钙 ) ,C组为高脂正常钙组 (含 0 5 %钙 ) ,D组为高脂高钙组 (含 1%钙 )。于第 10周末处死动物 ,腹主动脉取血测定血糖、血清胰岛素、瘦素和肿瘤坏死因子α的水平 ,应用RT -PCR法测定白色脂肪组织中re sistinmRNA的水平。结果 D组体重和体脂含量显著低于C组 (P <0 0 5 ) ,与A组相近 ;各组血糖差异无统计学意义 (P >0 0 5 ) ,D组胰岛素水平显著低于C组 (P <0 0 5 ) ,而胰岛素敏感指数显著高于C组 (P <0 0 5 ) ,与A组相近 ;A组、B组和D组的瘦素水平均显著低于C组 (P <0 0 5 ) ,校正了体重影响后 ,只有A组显著低于C组 (P <0 0 5 ) ;D组肿瘤坏死因子α水平显著低于C组 (P <0 0 5 ) ,与A组相近 ;C组与A组相比 ,白色脂肪组织中resistinmRNA表达增强 ,D组resistinmRNA表达比C组明显降低 ,B组resistinmRNA表达比C组增强。结论 高钙膳食不仅可以降低饮食诱导肥胖大鼠的体重 ,而且可以通过促进瘦素分泌 。

Objective To explore the effect of dietary calcium on the expression of resistin gene in white adipose tissue of obese rat induced by diet.Methods Obese rat model was induced by high-fat diet.Then obese rats were randomly divided into four groups and respectively fed with diffetent diets(basic diets,high-fat diet with 0.25% calcium,high-fat diet with 0.5%calcium,high-fat diet with 1% calcium)for 10weeks.At the end of experiment.the rats were sacrificed.Serum insulin.serum leptin,serum tumor necrosis factor α(TNFα) were measured with radioimmunity methods and the level of resistin mRNA was measured with reverse transcription polymerase chain reaction(RT-PCR) Results The weight and fat content in high-fat diet with 1% calcium group were significantly lower than those in high-fat diet with 0.5% calcium group.serum leptin in high-fat diet with 0.5% calcium group was higher than those in other groups,but after adjustment for the effect of weight,only the serum leptin in A group decreased significantly.The level of TNFα in high-fat diet with 1% calcium group significantly decreased compared with that in high-diet with 0.5% calcium group.Compared with A group.the resistin mRNA expression in high-fat diet with 0.5%calcium group increased significantly in white adipose tissue.While the resistin mRNA expression in high-fat diet with 0.25% calcium group incrased and that in high-fat diet with 1% calcium group decreased compared with high-fat diet with 0.5%calcium group.Conclusion High dietary calcium can not only reduce body weight and fat content,but also increase the serum leptin,decrease the TNFα and ingidit the expression of resistin gene in white adipose tissue to improve the insulin resistance,which contributed to the prevention of type 2 diabetes.