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Updated: Oct 13, 2025

Techniques of Sleeve Gastrectomy and Modified Roux-en-Y Gastric Bypass in Mice
Published on: March 20, 2017
The long-term failure of RYGB surgery in improving T2DM is related to hyperinsulinism
Gonzalo-Martín Pérez-Arana1, Alfredo Díaz Gómez2, José Bancalero de Los Reyes3
1Department of Human Anatomy and Embryology, Faculty of Medicine, University of Cadiz, Spain; Asociación Gaditana de Apoyo al Investigador (AGAI) Cádiz, Spain; Institute for Bi omedical Science Research and Innovation (INIBICA) University of Cadiz, Spain.
Background:
Roux-en-Y gastric bypass (RYGB) is the gold standard method for bariatric surgery and leads to substantial improvements in Type 2 Diabetes mellitus. However, many patients experience relapses in diabetes five years after undergoing this aggressive surgical procedure. We focus on beta-cell population changes and absorptive intestinal consequences after RYGB in a healthy nonobese animal model after a long survival period.
Methods:
For our purpose, we use three groups of Wistar rats: RYGB-operated, surgical control (Sham) and fasting control. We measure alpha-, beta-cell mass; transcription (Arx, and Pdx-1) and proliferation (Ki67) factors; glucose tolerance and insulin release after oral glucose tests; histological adaptive changes in the jejunum; and intestinal glucose transporters.
Results:
Our results showed an early increase in insulin secretion after surgery, that decrease at the end of the study. The beta-cell mass reduces twenty-four weeks after RYGB, which coincides with decrease of Pdx-1 transcription promoter factor. These was coincident with an increase in alpha-mass and a high expression of Arx in RYGB group.
Conclusions:
The analysis of all data showed beta-cell mass transdifferentiation into alpha-cell mass in RYGB rats. Due to long-term exhaustion of the beta-cell population by hyperinsulinism derived from digestive tract adaptation to surgery.
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