高脂饮食抑制胰岛素受体和胆囊收缩素受体在小鼠肝脏中的表达

High fat diet inhibits the expression of insulin receptor and cholecystokinin receptor in mouse liver

目的:在高脂饮食(HFD)小鼠中研究肝脏中胰岛素受体(IR)、胆囊收缩素(CCK)受体(CCKR)的表达和胰腺中胰岛素的储量。方法:用含15%和30%脂肪的两种HFD和对照餐(5%脂肪)喂养3组小鼠(15~16只/组)12周,用蛋白印迹法检测IR和CCKR在肝脏中的表达;用免疫组化和ELISA测定胰腺中β细胞群落和胰岛素含量;测定门静脉和外周血CCK和胰岛素水平。结果:15%和30%HFD使肝IR、CCKR的表达水平均下降(均P<0.05)。HFD还使胰岛β细胞面积增加(对照组:54.57±2.72;15%HFD:68.74±1.72;30%HFD:71.61±2.32;均P<0.05)。此外,30%HFD还增加胰腺胰岛素的储量并提升门静脉血浆中胰岛素的水平。结论:HFD降低小鼠肝脏IR和CCKR的表达,增加胰腺胰岛素储量。

Objective: To study the hepatic expression of insulin receptor(IR)and cholecystokinin(CCK)receptor(CCKR)and pancreatic storage of insulin in high fat diet(HFD)mice. Methods: Mice in three groups(15-16 per group)were fed with two HFDs with 15% and 30% fat and a control diet(5% fat). After 12 weeks,the expression of IR and CCKR in liver were detected by Western blotting. In the pancreas,β-cell area and insulin content were determined by immunohistochemistry and ELISA. CCK and insulin levels were measured in portal vein and peripheral blood. Results: Hepatic IR and CCKR expression was decreased by 15% and 30% HFDs(both P<0.05). The β-cell area of the pancreas was increased by both HFDs(control diet:54.57±2.72;15%HFD: 68.74±1.72;30%HFD:71.61±2.32;all P<0.05).Further,30% HFD increased both pancreatic insulin storage(P<0.05)and portal vein insulin. Conclusion: HFD decreases the expression of hepatic IR and CCKR and increases pancreatic insulin storage in mice.