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Updated: Jul 4, 2026
Roux-en-Y Gastric Bypass Operation in Rats
Published on: June 11, 2012
Gastric bypass surgery in rats produces weight loss modeling after human gastric bypass
David S Tichansky1, John D Boughter, Jason Harper
1Section of Minimally Invasive Surgery, Department of Surgery, College of Medicine, University of Tennessee Health Science Center, 910 Madison Ave., Suite 208, Memphis, TN, 38163, USA. dtichans@utmem.edu
Background:
The study of the mechanisms of weight loss after bariatric surgery requires an animal model that mimics the human procedure and subsequent weight loss. A rat model eliminates the cognitive efforts associated with human weight loss and gain.
Methods:
A technique for gastric bypass (Roux-en-Y gastric bypass [RYGB]) was developed in Sprague-Dawley rats. A 1- to 2-cc pouch is created from the uppermost stomach using a linear stapler. A 10-cm biliopancreatic limb and 15-cm Roux limb are anastomosed side to side with running nonabsorbable suture. The gastrojejunostomy is created with a single layer of running nonabsorbable suture. Four rats underwent RYGB. Weight loss was compared to four sham rats that had a midline incision and left 60 min with an open abdomen before closure.
Results:
RYGB rats lost an average of 16.5% body weight (BW) at 1 week, 22% BW at 2 weeks, 20% BW at 3 weeks, and 11% BW at 4 weeks. The RYGB rat's weight was basically level after 4 weeks. The shams lost an average of 4% BW at 1 week, 1% BW at 2 weeks, and 0% BW at 3 weeks and gained an average of 2% at weeks. Subjectively, the RYGB rats were less interested in chow and frequently had chow left in their cage.
Conclusion:
A Sprague-Dawley rat model for gastric bypass has been developed and yields approximately 11% BW loss. This will allow investigators to objectively view factors associated with weight loss without the confounding cognitive factors in humans.
