The Improvement of Hyperglycemia after RYGB Surgery in Diabetic Rats Is Related to Elevated Hypothalamus GLP-1 Receptor Expression

Abstract EN

Objectives.

This study aimed to explore the expression of GLP-1 receptor in hypothalamus and gastrointestinal tissues after Roux-en-Y gastric bypass (RYGB) surgery in diabetic rats.

Methods.

Male 12-week-old Wistar rats (control) and Goto-Kakizaki rats (diabetic) were randomly divided into two groups, respectively: control sham surgery group (C), control RYGB group (C + R), diabetic sham surgery group (D), and diabetic RYGB group (D + R).

Body weight and blood glucose were monitored before and after surgery every week.

Eight weeks after surgery, all rats were sacrificed and the serum fasting GLP-1 concentrations were measured by ELISA.

GLP-1R and DPP-4 expression in hypothalamus and ileum were measured by RT-PCR.

Results.

The body weight and fasting/random blood glucose in the D + R group decreased significantly compared with the D group ( P < 0.05 ).

Serum GLP-1 levels in diabetic rats treated with RYGB were higher than the corresponding sham surgery rats.

The expression of GLP-1R of hypothalamus in RYGB-treated diabetic rats was significantly higher than those of the sham surgery diabetic rats and both control group rats ( P < 0.05 ).

We found a negative correlation between hypothalamus GLP-1R mRNA and blood glucose level.

No significant difference was seen in ileum GLP-1R and DPP-4 expression among all groups.

Conclusions.

RYGB efficiently promoted serum GLP-1 levels and the expression of GLP-1 receptor in the hypothalamus in diabetic rats.

These data suggest that the hypothalamus GLP-1R may play an important role in the GLP-1 system for improving glucose homeostasis after reconstruction of the gastrointestinal tract.