Pancreas is a preeminent source of ghrelin after sleeve gastrectomy in Wistar rats

Many surgical techniques are employed in the treatment of severe obesity. A main consequence of these techniques is the improvement of type 2 Diabetes mellitus. Ghrelin is a gut hormone released in the gastric fundus and corpus, which has been related to diabetic improvement as mentioned in these papers. Sleeve gastrectomy and Roux-en Y Gastric Bypass are surgical techniques broadly employed in humans; both severely reduce the gastric surface. Paradoxically, the serum level of ghrelin in patients is preserved. We hypothesized about the role of embryonic pancreatic epsilon cells, which have the capacity to release ghrelin. We studied the changes in the epsilon cells and differentiation markers with immunostaining and ghrelin serum level and after surgery. We employed euglycemic male Wistar rats: two surgical groups (Sleeve gastrectomy and Roux-en Y Gastric Bypass) and two control groups. We reported a significant increase of ghrelin epsilon-cells in the pancreas and basal serum after Sleeve gastrectomy versus the control groups. The epsilon cellular increment was related to neogenesis, as the neurogenin-3 marker revealed. The Roux-en Y Gastric Bypass showed neither epsilon cell increase nor basal serum changes in ghrelin release. As a conclusion, we reported that the severe suppression of the fundus gastric produced the recovery of ghrelin released by the epsilon cells, which was indicative of an ontogenic embryonic pancreatic function.