Roux-en-Y gastric bypass-induced improvement of glucose tolerance and insulin resistance in type 2 diabetic rats are mediated by glucagon-like peptide-1.

Abstract

BACKGROUND:

The aim of this study was to investigate the effects of Roux-en-Y gastric bypass (RYGB) on glucose tolerance and insulin resistance in type 2 diabetic rats and the possible mechanisms involved in this process.

METHODS:

Thirty Goto-Kakizaki (GK) rats were randomly divided into three groups: RYGB operation, sham operation, and food restriction groups. Ten Wistar rats were used as non-diabetic control. The body weight and food consumption of rats were recorded 1 week before or every week after surgery. The fasting blood sugar and oral glucose tolerance test were performed using blood glucose meter. The levels of plasma insulin or glucagon-like peptide-1 (GLP-1) were evaluated by enzyme-linked immunosorbent assay. The insulin resistance was quantified using homeostasis model assessment method. The expression of GLP-1 receptor, Bcl-2, Bax, and caspase-3 was determined by Western blotting.

RESULTS:

Our results revealed that RYGB efficiently improved both glucose tolerance and insulin resistance in GK diabetic rats by upregulating GLP-1/GLP-1R expression. In addition, GLP-1R agonist exendin-4 dose-dependently increased insulin secretion in RIN-m5F cells and regulated the proliferation and apoptosis of these cells.

CONCLUSIONS:

RYGB provides a valuable therapeutic option for patients with type 2 diabetes. GLP-1 may contribute to the regulation of pancreatic β-cell function through its receptor following RYGB.

• Authors: Yuan Liu, Yong Zhou, Yong Wang, Donghua Geng, Jingang Liu
• Journal: Obesity surgery (Obes Surg) Vol. 21 Issue 9 Pg. 1424-31 (Sep 2011) ISSN: 1708-0428 [Electronic] United States
• PMID: 21479766 (Publication Type: Journal Article)

Chemical References

• Blood Glucose
• Glp1r protein, rat
• Glucagon-Like Peptide-1 Receptor
• Insulin
• Peptides
• Receptors, Glucagon
• Venoms
• Glucagon-Like Peptide 1
• Exenatide

Topics

• Animals
• Blood Glucose (metabolism)
• Blotting, Western
• Body Weight
• Cell Line
• Diabetes Mellitus, Type 2 (blood, metabolism, surgery)
• Eating
• Enzyme-Linked Immunosorbent Assay
• Exenatide
• Gastric Bypass
• Glucagon-Like Peptide 1 (blood)
• Glucagon-Like Peptide-1 Receptor
• Glucose Tolerance Test
• Insulin (blood, metabolism)
• Insulin Resistance
• Insulin-Secreting Cells (drug effects, metabolism)
• Male
• Peptides (pharmacology)
• Random Allocation
• Rats
• Rats, Wistar
• Receptors, Glucagon (agonists, metabolism)
• Venoms (pharmacology)