Effects of duodeno-jejunal bypass on glucose metabolism in obese rats with type 2 diabetes

Purpose

To evaluate the foregut and hindgut hypotheses for metabolic surgery in obese rats with diabetes.

Methods

Otsuka Long-Evans Tokushima fatty rats were divided into a sham operation group, a partial duodeno-jejunal bypass (P-DJB) group, and a complete DJB (C-DJB) group. P-DJB is a model to test foregut hypothesis, whereas C-DJB is a model to test both hypotheses. We performed oral glucose tolerance tests (OGTT) on all groups at baseline, and then 4 and 8 weeks postoperatively. The rats were killed thereafter and the plasma levels of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) were measured. A separate sub-group of C-DJB rats underwent OGTT after treatment with the GLP-1 antagonist, the PYY antagonist, or saline.

Results

Marked improvement of the blood glucose control during the OGTT was noted 8 weeks after C-DJB, but not 8 weeks after P-DJB or the sham operation. The serum GLP-1 and PYY levels were higher in the C-DJB group than in the other two groups. Pretreatment with the GLP-1 antagonist increased the blood glucose levels 30 min after the OGTT in the C-DJB rats.

Conclusions

Improvement in glucose metabolism after DJB was associated with the inflow of bile and pancreatic juice into the ileum, supporting validity of the hindgut hypothesis. GLP-1 appears to play a role in this improvement.