Objective: To investigate the relationship between the type 1 diabetic rats residual islet function and postoperative glycemia of gastric bypass procedure (GBP).
Methods: Intraperitoneal injection of STZ was used to produce type 1 diabetic rat model. According to the level of serum glucose, rats were divided into two groups: group 1 (fasting glucose 16.7-22.0 mmol/L, n=42) and group 2 (fasting glucose>22.0 mmol/L, n=54). Half rats of group 1 and group 2 received GBP, which were OP1 group (n=21) and OP2 group (n=27). The normal control group included 20 Wistar rats. The fasting glycemia and fasting C-peptide (C-P) were tested at postoperative weeks 1, 2, 3, and pancreas pathological slices were examined 3 weeks after surgery under microscope.
Results: After GBP, the C-P was elevated and the glycemia was well controlled in OP1 group compared with group 1 (P<0.05). But the C-P was not significantly increased and the glycemia control was poor compared with group 2 (P>0.05). Pathological examination revealed that there were partial islets residual in pancrease of group 1, the islets were shown obvious hyperplasia in OP1 group after GBP. There were almost no islets residual in pancrease of group 2, and the islets were shown no obvious hyperplasia in OP2 group after GBP.
Conclusions: Residual islet function determines the glycemia changes of type 1 diabetic rats after gastric bypass.