Abstract: Objective To investigate the effect of Roux-en-Y gastric bypass surgery on renal gluconeogenesis, and to explore the mechanism of improving glucose control and insulin sensitivity in obese rats. Methods Rats were randomly divided into the obese group (n=100) consumed high-fat diet (HFD) or the normal control group (NC group, n=20) consumed standardized diet. Top 30% of animals fed HFD by change in body mass were subdivided into three groups: obese control group (OB group, n=10), obese under RYGB group (RYGB group, n=10) or sham-operation (Sham group, n=10). Intraperitoneal glucose tolerance tests (IPGTT) were performed meanwhile the AUC of blood glucose concentration-time after surgery. Fasting glucose, insulin and lipid were measured respectively and HOMA-IR were calculated. The mRNA levels and protein levels of the key enzymes (G6P and PEPCK) of renal gluconeogenesis were examined with RT-PCR and Western blot respectively. Results Compared with OB group and Sham group, the level of body mass, lipid, blood glucose, insulin, HOMA-IR and AUG were significantly decreased (P<0.05), the expression of G6P and PEPCK mRNA and protein were significantly reduced (P<0.05) in RYGB group. Conclusions Roux-en-Y gastric bypass surgery can improve glucose control and insulin resistance, which may be related to decrease levels of mRNA and protein of G6P and PEPCK, weaken gluconeogenesis and glucose output in renal cortex.

Key words: Roux-en-Y gastric bypass, obesity, kidney, gluconeogenesis