Remodeling of the Residual Gastric Mucosa after Roux-En-Y Gastric Bypass or Vertical Sleeve Gastrectomy in Diet-Induced Obese Rats

Abstract

Whereas the remodeling of intestinal mucosa after bariatric surgeries has been the matter of numerous studies to our knowledge, very few reported on the remodeling of the residual gastric mucosa. In this study, we analyzed remodeling of gastric mucosa after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) in rats. Diet-induced obese rats were subjected to RYGB, VSG or sham surgical procedures. All animals were assessed for food intake, body-weight, fasting blood, metabolites and hormones profiling, as well as insulin and glucose tolerance tests before and up to 5 weeks post-surgery. Remodeling of gastric tissues was analyzed by routine histology and immunohistochemistry studies, and qRT-PCR analyses of ghrelin and gastrin mRNA levels. In obese rats with impaired glucose tolerance, VSG and RYGB caused substantial weight loss and rats greatly improved their oral glucose tolerance. The remaining gastric mucosa after VSG and gastric pouch (GP) after RYGB revealed a hyperplasia of the mucous neck cells that displayed a strong immunoreactivity for parietal cell H+/K+-ATPase. Ghrelin mRNA levels were reduced by 2-fold in remaining fundic mucosa after VSG and 10-fold in GP after RYGB. In the antrum, gastrin mRNA levels were reduced after VSG in line with the reduced number of gastrin positive cells. This study reports novel and important observations dealing with the remaining gastric mucosa after RYGB and VSG. The data demonstrate, for the first time, a hyperplasia of the mucous neck cells, a transit cell population of the stomach bearing differentiating capacities into zymogenic and peptic cells.

Intestinal Adaptations after Bariatric Surgery: Consequences on Glucose Homeostasis

“…Ghrelin is an orexigenic hormone produced mainly in the stomach and duodenum thatexerts gluco-regulatory functions [28].Resection of the fundic region in VSG leads to a decrease in ghrelin-expressing cells and concomitant ghrelin-circulating levels in rats [29,30] and humans [11,31,32]. Body weight and glucose tolerance measurements after VSG, however, showed similar results in ghrelin-deficient and in wild-type mice [33].…”

Differences in Alimentary Glucose Absorption and Intestinal Disposal of Blood Glucose After Roux-en-Y Gastric Bypass vs Sleeve Gastrectomy

“…Diet-induced obese rats were operated from Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (VSG) or sham surgery as described previously. 26…”

Serum Gastric Biomarker Levels After Sleeve Gastrectomy and Roux-en-Y Gastric Bypass Operations: A Prospective Study with 1-year Follow-up

“…It should be noted that PGII is produced not only in the corpus but also in the other parts of the stomach (antrum, fundus, duodenum). The above changes can be explained by mucous neck cell hyperplasia, which has been demonstrated in recent animal experiments (4).…”

“…The two major currently used weight loss surgeries are laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) (1)(2)(3). The fundamental difference between these two operations is that in LSG only the anatomy of the stomach is changed, due to a large vertical gastric resection, without bypassing the stomach, in contrast to LRYGB (4). The sequelae in gastric physiology caused by bariatric operations are persistent and will act over many postoperative years.…”