Metabolism and Gastric Remnant Changes after Roux-en-Y Gastric Bypass in Rats

Background: The Roux-en-Y gastric bypass (RYGB) may affect metabolism, microbiology, and histology of gastric remnant. Therefore, this study aimed to investigate these issues in rats. Methods: Twelve rats were randomly allocated to a RYGB group (n == 6) and nonoperated normal rats group (n == 6). After 30 postoperative days, all rats were injected with 0.1ml of Na<SU99m</SUTc<SU--</SU i.v. (radioactivity 0.66 MBq). After 30 min, liver, stomach, thyroid, heart, lung, kidney, and femur samples were harvested and weighed. Percentage radioactivity per gram of organ (%%ATI/g) was determined using a Perkin-Elmer gamma counter. Serum albumin, calcium, aminotransferases (ALT, AST), T3, T4, and PTH were determined. Samples of the excluded stomach mucosa were harvested for bacterial and fungal count such as colony-forming units/g and histology. Results: A significant reduction (t test) in %%ATI/g was observed in the liver, stomach, and femur in the RYGB rats, compared with normal rats (p < .05). A significant reduction in serum albumin and calcium in RYGB rats was detected, compared with normal rats (p < .05). ALT and AST were significantly different between the two groups. T3 and T4 levels were significantly lower in RYGB rats than in normal rats (p < .05); PTH levels were higher in RYGB rats than in controls (p == .009). The gastric remnant mucosa of RYGB rats showed higher bacterial and fungal count, atrophy, intestinal metaplasia, and neutrophilic polymorphonuclear inflammation than in normal rats. Conclusions: This investigation demonstrated that a model of murine RYGB significantly modified metabolic parameters and the microbiology/histology of the remnant stomach.