Bariatric surgery influences β-cell turnover in non obese rats

The aim of this study was to investigate the relation between the different bariatric surgeries and pancreatic β-cell turnover.

We used healthy adult male Wistar rats to undergo the different techniques. Three surgical techniques were developed (malabsorptive, Sleeve gastrectomy and Roux-Y Gastric Bypass-), together with two control groups (Sham and fasting control). Pancreatic β-cell mass was measured, as well as apoptosis, proliferation and neogenesis related to cellular turnover. Otherwise, we measured the functional issues to elucidate the physiological role that these surgical techniques trigger in the carbohydrate metabolism (e.g. food intake, weight gain, intraperitoneal glucose tolerance test, and basal glycaemia). Results included the differences in phenotypes of the rat after the surgery. The rats did not show important differences in glycaemic parameters between the surgical groups. The β-cell mass presented modifications related with proliferation processes. A significant increase of β-cell mass in the malabsorptive technique was reported. On the other hand, the peripheral resistance to insulin tended to be reduced in rats which underwent malabsorptive and mixed techniques.

This work showed an increase in β-cell mass after the resection of an important portion of small bowel. The Roux-Y Gastric Bypass produced a non-significant increase in β-cell mass. We considered that these implications of surgery over the endocrine pancreas must be one of the mechanisms related to the improvement of type 2 Diabetes mellitus following bariatric surgery.