Impact of the hepatic branch of the vagus and Roux-en-Y gastric bypass on the hypoglycemic effect and glucagon-like peptide-1 in rats with type 2 diabetes mellitus.

Background: The impact of the hepatic branch of the vagus and Roux-en-Y gastric bypass (RYGB) on the hypoglycemic effect and glucagon-like peptide-1 (GLP-1) in rats with type 2 diabetes mellitus (T2DM) was investigated, and interactions were preliminarily analyzed.

Methods: A total of 45 rats with T2DM were divided into four groups: sham operation (S, n = 10), sham operation with the hepatic branch of the vagus resected (SV, n = 11), RYGB (n = 12), and RYGB without preservation of the vagus (RYGBV, n = 12). Body mass, fasting blood glucose (FBG), fasting serum insulin, and concentrations of fasting serum GLP-1 were examined in the first, second, fourth, and eighth week before and after surgery. The effects of RYGB and the hepatic branch of the vagus on GLP-1 levels in the eighth postoperative week were also analyzed.

Results: RYGB caused a significant reduction in the weight of rats with T2DM (P < 0.05), improved the levels of serum GLP-1 and insulin (P < 0.05), and decreased FBG level (P < 0.05). Retention of the hepatic branch of the vagus maintained weight reduction for a longer period (P < 0.05) and increased the levels of serum GLP-1 and insulin (P < 0.05), but had no impact on FBG level (P > 0.05).

Conclusions: RYGB had better therapeutic efficacy in rats with T2DM. Care should be taken during RYGB surgery to preserve the hepatic branch of the vagus.