Objective:To investigate the effect of Roux-en-Y gastric bypass(RYGB)on glycogen synthase kinase-3β(Gsk-3β)and glycogen synthase(Gs)

and to explore the mechanism of improving hepatic glycogen synthesis in obese rats. Methods:Sixty SD rats randomly chosen from 70 rats were fed with high-fat diet(HFD)

and the left 10 rats which fed with standardized diet were used as normal control group(n=10). Twenty-six rats in the HFD group having body weight at least 20% more than those in normal control rats were subdivided into three groups:obese group(Ob group

n=8)

obese RYGB group(Ob+RYGB group

n=10)

obese sham operation group(Ob +sham group

n =8). Intraperitoneal glucose and insulin tolerance tests(GTT and ITT) were performed after surgery.Hepatic glycogen deposition was observed using periodic acid schiff(PAS)staining. The m RNA levels and protein levels of Gsk-3βand Gs were examined with quantitative RT-PCR and Western blot respectively. Fasting blood glucose(FBG) and plasma levels of insulin also were tested at 8 week after surgery. Results:The number of rats in each group after successful modeling was 9

8

7 and 7

respectively. Compared with those in control group

the level of body weight

FBG

plasma insulin

homeostasis model assessment of insulin resistance

the area under curve of GTT and ITT were significantly increased(P<0.05)

hepatic glycogen content was decreased obviously

the expression of Gsk-3β were significantly increased(P<0.05)

and the expression of Gs were significantly decreased(P<0.05)in Ob group and Ob+Sham group

which were dramatically reversed by RYGB treatment(P<0.05). Conclusion:RYGB can significantly promote hepatic glycogen synthesis in obese rats

which may be related to the inhibition of Gsk-3β and improvement of Gs expression.