Study Of Roux-en-Y Gastric Bypass And Gastric Banding On Rats With Type 2 Diabetes

Objective: To contrast the effect of Roux-en-Y Gastric Bypass (RYGB) and Gastric banding on rats with STZ-induced type 2 diabetes, and to clarify its initial mechanism.Subject:SD male rats and SD rats with type 2 diabetesMethods:40 rats with type 2 diabetes were randomly allocated into four groups: Roux-en-Y Gastric Bypass group (group RYGB, n=10); Gastric banding group (group GB, n=10); diet control group (group F, n=10); control group (group C, n=10). The fasting blood glucose, fasting plasma IGF-1, fasting plasma leptin, fasting plasma insulin, weight and food-intake, operation time, death rate were also measured before operation and after operation for 1, 2, 3 ,4, 8and 16weeks.Results:The fasting blood glucose of the group GB descend to 12.6±3.7mmol/L, the fasting plasma insulin rose up to 58.7±8.5mU/L, the fasting Plasma leptin descend to 14.6±3.3pg/ml, the weight descend to 212.6±15.1g. There were significant differences between before and after operation for 16 weeks (P <0.01). In RYGB group, The fasting blood glucose descend to 8.8±4.9mmol/L in the 16th week, the fasting insulin IGF-1 rise to 148.6±7.3ng/L, the fasting plasma insulin rise to 14.1±3.5pg/ml, the fasting Plasma leptin descend to 14.1±3.5pg/ml, the weight is 200±15.1g. There were significant differences between before and after operation 16th week (P <0.01). There were significant differences of the fasting blood glucose, fasting plasma insulin, IGF-1 and the food-intake between group GB and group RYBG the 2nd week after operation(P <0.05). Compared the fasting plasma insulin and the weight of group GB and group RYBG in the 3rd week of operation, there were significant differences (P <0.05), and there were no significant differences in other time. There were significant differences of the operation time and the survival rate between group GB and group RYBG after operation(P <0.01); There were significant differences of the fasting plasma insulin and the fasting Plasma leptin between group F and group GB during the 3rd to 4th week after operation (P <0.05). Compared the weight of the group F and the group GB in the third week of operation, there were significant differences (P <0.05), and there were no significant differences in other time. The fasting blood glucose of the group F and the group GB has no significant differences between before and after operation (P <0.05).Conclusion:The group of RYGB can improve fasting blood glucose earlier, which was more effective than the groups of GB and F. Alimentary control, the changes of levels of fasting plasma insulin and leptin worked together at the mechanisms of lowering blood glucose in groups of RYGB and GB. The change of plasma insulin played important role in the the mechanisms of lowering blood glucose of models with Roux-en-Y gastric bypass operation, which suggested that the change of IGF-1 may be the major mechanism of blood glucose changing in STZ-induced type 2 diabetes rat after Roux-en-Y gastric bypass operation, while the alimentary control may be the major mechanism of blood glucose changing in STZ-induced type 2 diabetes rat after Gastric banding operation. In addition, the operation time and survival rate of GB group were better than the group of RYGB.