西格列汀对肥胖大鼠血清及不同组织视黄醇结合蛋白4表达水平的影响

目的：研究西格列汀对肥胖大鼠代谢指标、血清视黄醇结合蛋白4(RBP4)及附睾脂肪、肝脏组织 RBP4表达水平的影响。方法将40只SD大鼠随机分为对照组( ND组,n=10)和高脂组(HD组,n=30)。16周后HD组成功建立肥胖模型(n=16),并随机分为肥胖对照组(OB组,n=8)、西格列汀干预组( SITA 组, n =8)。分别测定干预前后体重(BW)、空腹血糖(FBG)、三酰甘油(TG)、胆固醇(TCH)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)、空腹胰岛素( FINS)及血清RBP4水平,并计算胰岛素抵抗指数( HOMA-IR)。 Western blot法检测大鼠附睾脂肪和肝脏组织RBP4表达水平。结果①与 ND 组相比, HD 组 BW、FBG、TG、TCH、LDL-C、FINS、HOMA-IR、RBP4升高,HDL-C降低,差异有统计学意义(P <0．05,P <0．01)。在 HD 组中,OB 组、SITA组间各指标差异无统计学意义。西格列汀干预后, SITA 组较 OB 组 FBG、TG、TCH、LDL-C、FINS、HOMA-IR、RBP4降低,HDL-C升高,差异有统计学意义( P<0．05,P<0．01)。②与ND组比较,OB组附睾脂肪RBP4蛋白表达水平显著增加( P <0．05)；与 OB 组相比, SITA 组附睾脂肪RBP4蛋白表达水平显著降低( P<0．01)。③ Pearson相关分析显示ND组、血清RBP4与TG呈正相关性；HD组、血清RBP4与FINS、HOMA-IR、TG、附睾脂肪 RBP4呈正相关性,与HDL-C呈负相关性。结论肥胖大鼠血清RBP4水平升高,附睾脂肪RBP4表达水平增高。西格列汀干预能显著降低肥胖大鼠血清RBP4水平及附睾脂肪中RBP4蛋白表达水平,并可改善糖脂代谢。

Effects of treatment with sitagliptin on serum and different tissue retinol binding protein 4 expression levels in high-fat-fed obesity rats

Objective To evaluate the effects of treatment with sitagliptin on metabolic parameters, serum retinol binding protein 4 (RBP4) levels, epididymal adipose tissue and liver RBP4 expression levels in high-fat-fed obese rats . Methods 40 SD rats were randomly divided into normal diet group (ND group, n=10) and high fat diet group (HD group, n=30). 16 weeks later, obese models (n=16) were established from HD group and were ran-domly divided into obesity group ( OB group, n=8 ) and sitagliptin group ( SITA group, n=8 ) . Measure body weight ( BW) , fasting blood glucose ( FBG) , triglyceride ( TG) , total cholesterol ( TCH) , high-density lipoprotein ( HDL-C) , low-density lipoprotein ( LDL-C) , fasting insulin ( FINS) , serum RBP4 respectively before and after the 6 weeks of treatment, and calculate homeostasis model assessment-insulin resistance index( HOMA-IR) . West-ern blot was used to detect the epididymal adipose tissue and liver RBP4 protein expression levels. Results ①The levels of BW, FBG, TG, TCH, LDL-C, FINS, HOMA-IR and serum RBP4 in HD group increased while the levels of HDL-C decreased compared with those of ND group with a statistical significance (P<0. 05,P<0. 01). The differences between OB group and SITA group were of no statistical significance. After treatment with sitaglip-tin, the levels of FBG, TG, TCH, LDL-C, FINS, HOMA-IR and serum RBP4 of SITA group decreased while the levels of HDL-C increased compared with those of OB group with a statistical significance (P<0. 05,P<0. 01).② Epididymal adipose tissue RBP4 protein expression levels in OB group increased compared with ND group ( P<0. 05 ) , epididymal adipose tissue RBP4 protein expression levels in SITA group decreased compared with OB group (P<0. 01). ③ Pearson correlation analysis showed that in ND group, serum RBP4 was positively correlated with TG. In HD group, serum RBP4 and FINS, HOMA-IR, TG,epididymal adipose tissue RBP4 were positively corre-lated and negative correlation existed between serum RBP4 and HDL-C. Conclusion Serum and epididymal adi-pose tissue RBP4 protein levels are elevated in obesity rats. Sitagliptin intervention can lower serum and epididymal adipose tissue RBP4 protein levels in obesity rats and improve the glucose and lipid metabolism.