ObjectiveTo investigate the effect and mechanism of gastric bypass surgery (GBP) on fasting bloo-glucose (FBG) in type 2 diabetic rats. MethodsThe models of type 2 diabetic rats were induced by stretozotocin and 20 diabetic rats were randomly divided into two groups: diabetes-operation group (DO group, n=10) and diabetes-control group (DC group, n=10). Another twenty normal rats were randomly divided into two groups: normaloperation group (NO group, n=10) and normal-control group (NC group, n=10). The rats underwent GBP in DO group and NO group and sham operation in DC group and NC group. The FBG levels, serum dipeptidyl peptidase Ⅳ (DPPⅣ), and glucagon-like peptide-1 (GLP-1) concentrations of rats in each group were detected before operation and at 72 h, on 1 week, 4 weeks, and 8 weeks after operation. ResultsThe FBG levels of rats before operation were not significantly different between DO group and DC group or between NO group and NCgroup (Pgt;0.05). After operation, the FBG levels of rats in DO group gradually declined, reached the bottom on 4 weeks after operation and rose slightly on 8 weeks; The FBG levels of rats in DO group were lower after operation than before operation (Plt;0.05); After operation the FBG levels of rats in DO group were higher than that in NO group and NC group at the same time point (Plt;0.05); In DC group, the difference of FBG levels of rats at different time point was not statistically significant (Pgt;0.05); The inter-group and intra-group difference of FPG levels of rats for NO group and NC group was not statistically significant (Pgt;0.05). The concentrations of serum DPP-Ⅳ of rats before operation were not significantly different in each group (Pgt;0.05). After operation, the concentrations of serum DPP-Ⅳ of rats in DO group and NO group gradually decreased and markedly lower than that before operation, respectively (Plt;0.05). The concentrations of serum DPP-Ⅳ of rats after operation in DO group and NO group were significantly lower than that at the same time point in DC group and NC group, respectively (Plt;0.05); The intragroup difference of serum DPP-Ⅳ concentrations of rats for DC group and NC group was not statistically significant (Pgt;0.05). The concentrations of serum GLP-1 of rats before operation were not significantly different between DO group and DC group or between NO group and NC group (Pgt;0.05). After operation, the concentrations of serum GLP-1 of rats in DO group and NO group gradually increased, reached the top on 4 weeks after operation and declined slightly on 8 weeks; The concentrations of serum GLP-1 of rats in DO group and NO group were higher after operation than before operation (Plt;0.05);After operation, the concentrations of serum GLP-1 of rats in NO group were higher than that in NC group (Plt;0.05), but the concentrations of serum GLP-1 of rats at different time point in NO group were not different (Pgt;0.05). The intragroup difference of serum GLP-1 concentrations of rats for DC group and NC group was not statistically significant (Pgt;0.05). ConclusionsThere is obvious hypoglycemic effect of GBP on FBG levels of type 2 diabetic rats other than normal rats, in which high secretion of GLP-1 and low secretion of DPP-Ⅳ may be play an important role.