Gastric Bypass Surgery Induces Changes in Gut Hormone-Producing Cell Populations in a Porcine ModelAndreas Lindqvist1, Mikael Ekelund2, Stefan Pierzynowski3, Leif Groop1, Jan Hedenbro2,4 and Nils Wierup1*
- *Corresponding Author:
- Nils Wierup
Department of Clinical Sciences in Malmö
Lund University Diabetes Centre Clinical Research Centre
Jan Waldenströms gata 35, Malmö, Sweden
E-mail: [email protected]
Received date: August 24, 2015; Accepted date: September 05, 2015; Published date: September 09, 2015
Citation: Lindqvist A, Ekelund M, Pierzynowski S, Groop L, Hedenbro J, et al. (2015) Gastric Bypass Surgery Induces Changes in Gut Hormone-Producing Cell Populations in a Porcine Model. J Diabetes Metab 6:602. doi:10.4172/2155-6156.1000602
Copyright: © 2015 Lindqvist A, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: In most patients gastric bypass (GBP) causes remission of type 2 diabetes. It is established that plasma levels of gut hormones are affected by GBP, but it is not well understood how the enteroendocrine cells producing these gut hormones are affected by GBP. Objectives: We set out to investigate the effect of GBP on enteroendocrine cells in the stomach and intestine of pigs. Methods: Lean non-diabetic pigs were subjected to either GBP or sham-surgery and immunocytochemistry and morphometry for all major gut hormones in all parts of the GI-tract was performed. Sham-operated, pair-fed pigs were used as controls. Results: Postoperatively in the antrum, the density of gastrin-cells was lower (GBP 12.8±2.1 cells/μm2 versus sham 21.3±2.6 cells/μm2 ) while density of serotonin-cells was higher in GBP-pigs (GBP 21.6±2.3 cells/μm2 versus sham 10.6±0.7 cells/μm2). In the fundus, no effect of GBP was observed on any cell population. In the duodenum, densities of CCK- (GBP 5.1±1.0 cells/μm2 versus sham 2.6±0.4 cells/μm2), ghrelin- (GBP 3.4±0.5 cells/μm2 versus sham 1.4±0.2 cells/μm2), GIP- (GBP 5.5±0.3 cells/μm2 versus sham 2.3±0.3 cells/μm2) and neurotensin-cells (GBP 3.5±0.7 cells/μm2 versus sham 0.5±0.2 cells/μm2) were higher in the GBP-pigs. In the distal jejunum, density of ghrelin-cells was lower (GBP 0.7±0.2 cells/μm2 versus sham 2.3±0.4 cells/μm2) while densities of GIP- (GBP 3.5±0.3 cells/μm2 versus sham 2.4±0.2 cells/μm2) and secretin-cells (GBP 3.4±0.7 cells/μm2 versus sham 1.6±0.3 cells/ μm2) were higher in GBP-pigs compared to sham-pigs. In the ileum, densities of GIP-cells (GBP 5.4±0.4 cells/ μm2 versus sham 3.9±0.4 cells/μm2) and somatostatin-cells (GBP 3.3±0.4 cells/μm2 versus sham 2.1±0.3 cells/μm2) were higher, while densities of GLP-1-cells (GBP 5.0±0.5 cells/μm2 versus sham 8.8±1.4 cells/μm2) and PYYimmunoreactive cells (GBP 3.8±0.1 cells/μm2 versus sham 5.9±0.8 cells/μm2) were lower in the GBP-pigs. In the colon, densities of GIP- (GBP 2.8±0.3 cells/μm2 versus sham 1.4±0.2 cells/μm2), serotonin- (GBP 6.7±0.3 cells/μm2 versus sham 4.8±0.5 cells/μm2) and somatostatin-cells (GBP 1.9±0.2 cells/μm2 versus sham 1.3±0.1 cells/μm2) were higher in the GBP-pigs. GBP had no effect on villi length or total mucosa height in any of the intestinal segments analyzed, whereas duodenum (GBP 37.6±3.4 cells/μm2 versus sham 26.5±2.8 cells/μm2) and ileum (GBP 127±1.2 cells/μm2 versus sham 84.7±9.9 cells/μm2) of the GBP-pigs displayed higher proliferation, as assessed by Ki67 immunoreactivity. Conclusions: We conclude that GBP induces rapid and profound changes in the densities of gut hormoneproducing cells throughout the GI-tract in pigs. These changes seem to be the result of GBP per se and not a result of body weight or food intake. Also, GIP was increased in the GBP-pigs in all the intestinal segments analyzed.