title: Roux-en-Y gastric bypass increases hepatic and peripheral insulin sensitivity in rats with type 2 diabetes mellitus.
abstract: BACKGROUND
  Roux-en-Y gastric bypass (RYGB) surgery for the treatment of obesity leads to long-term diabetes remission in approximately 80% of cases. The aim of this study was to investigate the effects of RYGB on hepatic and peripheral insulin sensitivity in type 2 diabetic rats and their possible mechanisms. We also tested the hypothesis that RYGB reduces lipid content and improves insulin sensitivity in hepatocytes and skeletal muscle cells.
  
  
  METHODS
  Sprague-Dawley rats were divided into 4 groups: diabetic RYGB group (n = 18), diabetic RYGB sham group (n = 6), diabetic group (n = 6), and nondiabetic control group (n = 6). The hyperinsulinemic-euglycemic clamp with tracer infusion was completed at 2, 4, and 8 weeks postoperatively to assess insulin sensitivity. The lipid content in liver and muscle tissue was examined.
  
  
  RESULTS
  Postoperatively, the diabetic RYGB group had significant decreases in weight, fat mass, and food intake. Two weeks after surgery, RYGB had significantly improved the hepatic insulin sensitivity index and decreased the hepatic triglyceride, total cholesterol, and fatty acyl-CoA content. The significantly increased insulin sensitivity and decreased lipid content in muscle were not detected until 4 weeks after RYGB surgery. The basal insulin and C-peptide concentrations were significantly lower than those in diabetic group by 2 weeks after RYGB.
  
  
  CONCLUSIONS
  The increased insulin sensitivity after RYGB occurs earlier in the liver than in the muscle and both may contribute to long-term remission of type 2 diabetes. Reduced lipid content of hepatocytes and skeletal muscle cells after RYGB may contribute to the improved insulin sensitivity in these cells.
authors: Department of Endocrinology, Shengjing Hospital of China Medical University, Shen Yang, People׳s Republic of China.
authors: Bing
authors: B
authors: He
authors: Department of Endocrinology, Shengjing Hospital of China Medical University, Shen Yang, People׳s Republic of China.
authors: Li
authors: L
authors: Chen
authors: Department of Endocrinology, Shengjing Hospital of China Medical University, Shen Yang, People׳s Republic of China.
authors: Cong
authors: C
authors: Yu
authors: Department of Endocrinology, Shengjing Hospital of China Medical University, Shen Yang, People׳s Republic of China.
authors: Dongxu
authors: D
authors: Piao
authors: Department of General Surgery, Shengjing Hospital of China Medical University, Shen Yang, People׳s Republic of China.
authors: Yong
authors: Y
authors: Wang
authors: Department of Endocrinology, Shengjing Hospital of China Medical University, Shen Yang, People׳s Republic of China. Electronic address: hb3h@hotmail.com.
authors: Ping
authors: P
authors: Han
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000097:blood* / Q000601:surgery; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000601:surgery; D015390:Gastric Bypass / Q000379:methods*; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology*; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008055:Lipids
keywords: Insulin resistance; Lipotoxicity; Obesity; Roux-en-Y gastric bypass; Type 2 diabetes mellitus