OBJECTIVETo observe postoperative glucose tolerance, gastric inhibitory polypeptide (GIP) , and glucogan-like peptide-1 (GLP-1) in normal glucose level dogs after undergoing gastric bypass procedures, and to explore the mechanism of gastric bypass procedures to treat type 2 diabetes.

METHODSThe 6 dogs with normal glucose tolerance had undergone gastric bypass procedures, and measure preoperative and postoperative oral and intravenous glucose tolerance (at time points 1, 2, and 4 weeks) through changes in blood glucose, insulin, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and measure preoperative and postoperative week 4 pancreatic tissue morphology.

RESULTSSecond weeks after operation, the fasting blood sugar was (3.58 ± 0.33) mmol/L, and significantly lower than preoperative (t = 3.571, P < 0.05). The GLP-1 level before oral glucose tolerance test (OGTT) and 30 minutes after OGTT were (0.90 ± 0.21) and (0.91 ± 0.19) pmol/L respectively, and significantly higher than preoperative (t value were -3.660 and -2.971, P < 0.05). GLP-1 levels began to decrease in the second week after surgery. After 4 weeks, the index recovered to the preoperative level. Four weeks after surgery when compared with preoperative, islet morphology, islet number (6.8 ± 0.8 and 7.1 ± 0.8 respectively) and islet cells (16.7 ± 2.5 and 16.3 ± 3.1 respectively) did not change significantly (P > 0.05).

CONCLUSIONGastric bypass procedures could be briefly affect normal glucose tolerance in dogs' blood glucose, insulin and diabetes-related gastrointestinal hormones.