胰岛素抵抗模型大鼠视黄醇结合蛋白4和8-羟基脱氧鸟苷表达水平的变化及运动和吡格列酮干预作用的观察

目的 观察IR模型大鼠视黄醇结合蛋白4（RBP4）和8-羟基脱氧鸟苷（8-OHdG）表达水平及运动和吡格列酮的干预作用。方法 40只雄性Wistar大鼠随机分为对照（NC）组和模型（M）组，分别给予普通和高糖高脂饲料，8周后再将M组随机分为IR组、运动（Exercise）组和吡格列酮（Pio）组，后2组分别进行游泳训练及吡格列酮灌胃，持续8周。16周末采用稳态模型评估胰岛素抵抗指数（HOMA-IR）、血清RBP4、骨骼肌超氧化物歧化酶（SOD）及8-OHdG。结果 （1）IR组HOMA-IR、RBP4升高、8-OHdG增强（P〈0.01），SOD降低（P〈0.01）;Exercise、Pio组HOMA-IR、RBP4、8-OHd下降，SOD增加（P〈0.05）。（2）相关性分析发现，HOMA-IR与RBP4、8-OHdG正相关（r=0.690、0.628，P〈0.01），与SOD负相关（r=-0.712，P〈0.01）;RBP4与8-OHdG正相关（r=0.656，P〈0.01），与SOD负相关（r=-0.649，P〈0.01）。结论 RBP4可能通过增加IR大鼠氧化应激参与IR，运动、吡格列酮可能通过抑制IR大鼠氧化应激，降低RBP4改善IR。

Expression changes of RBP4 and 8-OHdG in insulin-resistant rats and their effects of exercise and pioglitazone intervention

Objective To observe the expression of retinol binding protein4（RBP4） and 8-hydroxy-2＇-deoxyguanosine （8-OHdG） in insulin resistant （IR） rats and their effect of exercise and pioglitazone intervention. Method A total of 40 male Wistar rats were randomly divided into a control group fed normal diet and a model group fed high sugar and high fat diet. Eight weeks later, the model group was randomly divided into an IR group, an exercise group and a pioglitazone group. The latter two groups rats of performed swimming training and received pioglitazone a daily dose of20 mg/（kg.d） ]for eight weeks. At the end of sixteen weeks of experiment, the homeostasis model was used for assessment of insulin resistance index （HOMA-IR）, and the serum levels of RBP4 , the activity of skeletal muscle superoxide dismutase （SOD） and the expression levels of 8-OHdG in skeletal muscle were measured. Results （1）The levels of HOMA-IR, RBP4 and 8-OHdG were higher in IR group than in control group（P〈0.01）, while the activity of SOD were lower in IR group than in control group（P〈0.01）. After the intervention of exercise/ pioglitazone, the levels of HOMA-IR, RBP4 and 8-OHdG were decreased（P〈0.05）and SOD activity were increased（P〈0.05）. （2） Correlation analysis showed that HOMA-IR had a positive correlation with the expression levels of RBP4 and 8-OHdG （r=0.690,0.628,P〈0.01）, and a negative correlation with the activity of SOD （r=-0.712,P〈0.01. The RBP4 had a positive correlation with the expression levels of 8-OHdG （r=0.656,P〈0.01）, and a negative correlation with the activity of SOD （r=-0.649,P〈0.01）. Conclusion RBP4 could participate in IR through increasing oxidative stress of IR group rats , and exercise and pioglitazone could decrease RBP4 to improve IR by inhibiting oxidative stress of IR group rats.