高脂诱导胰岛素抵抗大鼠对不同脂肪组织水通道蛋白7的影响

Effects of aquaporin 7 in different adipose tissues of rats with insulin resistance

目的研究胰岛素抵抗大鼠不同脂肪组织水通道蛋白7(AQP7)的表达水平,探讨AQP7与脂肪组织发生胰岛素抵抗的关系。方法 20只雄性SD大鼠随机分为对照组(CG)和高脂喂养诱导胰岛素抵抗模型组(IRG)。观察两组大鼠体重变化,检测TG、TC、HDL-C、LDL-C、甘油、空腹血糖(FBG)、空腹胰岛素(FINS)及脂肪因子的水平,同时比较皮下脂肪和附睾脂肪组织AQP7 m RNA、蛋白以及不同脂肪组织蛋白激酶B(PKB)及磷酸化蛋白的表达水平。结果至12周末,IRG组较CG组血清LDL、FBG、FINS、IL-6、TNF-α及胰岛素抵抗指数(HOMA-IR)明显升高(P<0.05或0.01),而HDL、脂联素水平下降(P<0.05)。对m RNA和蛋白检测发现,在IRG组中内脏脂肪组织AQP7表达水平高于皮下脂肪组织,并且较CG组升高。在IRG组中内脏脂肪组织PKB磷酸化蛋白表达水平较皮下脂肪表达下降,并且较CG组下降。结论内脏脂肪组织AQP7的异常表达,可能与胰岛素抵抗的发生有关。

Objective To investigate the expression of aquaporin 7（AQP7） in different adipose tissues of insulin resistance rats. Methods Male SD rats were randomly divided into insulin resistant and control groups with 10 animals in each. The insulin resistance model was induced by feeding with high-fat diet. The changes of body weight, serum triglyceride, cholesterol, high density lipoprotein, low density lipoprotein, glycerol, fasting blood glucose, insulin and adipokines in two groups were observed. The expression of AQP7 m RNA and protein, and the expression of PKB and phosphorylated protein in subcutaneous adipose tissue（SAT） and epididymal adipose tissue（visceral adipose tissue, VAT） were detected and compared. Results Compared to control group, the serum low density lipoprotein, fasting blood glucose, insulin, IL-6, TNF-α and HOMA-IR in insulin resistance group were higher（P0.01 or P0.05）, while high density lipoprotein and adiponectin were lower（P0.05） at 12 th week after high diet feeding.The level of AQP7 expression in VAT was higher than that in SAT, and the expression of AQP7 in VAT of insulin resistance group was higher than that of control group in both gene and protein level. The expression of PKB phosphorylated protein in VAT was lower than that in SAT, and the expression level in insulin resistance group was lower than that in control group. Conclusion The abnormal expression of AQP7 in visceral adipose tissue may be related to the occurrence of insulin resistance.