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Lee, Jung, Jeon, and Kim: Effect of Roux-en-Y Gastric Bypass on Body Weight, Ghrelin and PYY3-36 in Diet-induced Obese Rats
Original Article
Journal of the Korean Surgical Society

Journal of the Korean Surgical Society 2010; 79(3): 155-162.

Published online: 3 September 2010

DOI: https://doi.org/10.4174/jkss.2010.79.3.155

Effect of Roux-en-Y Gastric Bypass on Body Weight, Ghrelin and PYY3-36 in Diet-induced Obese Rats

Sang Kuon Lee, M.D., Hun Jung, M.D., Hae Myung Jeon, M.D., Eung Kook Kim, M.D.

Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.

Corresponding author (luislee@catholic.ac.kr)

Received 5 March 2010       Accepted 15 June 2010

Copyright © 2010 The Korean Surgical Society

Abstract

Purpose

Obesity is considered an epidemic worldwide. Nonsurgical treatment such as dietary, physical and pharmacological therapies have limited success and thus, bariatric surgery is the ultimate option. Roux-en-Y gastric bypass (RYGB) is a bariatric procedure, which is a restrictive and malabsorptive procedure simultaneously. The purpose of this study was to develop surgical rat models of bariatric surgery and analyze the effect of gastric bypass on body weight, ghrelin and polypeptide YY3-36 (PYY3-36) changes in rats.

Methods

RYGB, sleeve gastrectomy (SG) and sham operation were performed in diet-induced obese rats and compared to obese control and normal control rats.

Results

In RYGB group, 20.7±8.56% of weight loss was achieved on postoperative day 18 and maintained thereafter. This outcome was significant compared to SG (8.8±1.82%) and sham operated (6.2±2.45%) groups. When pre- and postoperative ghrelin levels were compared, there was a significant decrease in RYGB group (P<0.028); nonetheless, there was no difference in SG and sham operated groups. When pre- and postoperative PYY3-36 levels were compared, there was a significant increase in RYGB (P<0.028), SG (P<0.031) and sham operated (P<0.031) groups.

Conclusion

We developed surgical rat models of RYGB and SG. Those rats that underwent RYGB lost significant body weight and maintained the weight thereafter. The decrease in ghrelin and increase in PYY3-36 may be associated with loss of appetite and delay in intestinal transit time with subsequent weight loss maintenance. In the future, this rat model would serve as a tool for further study on endocrine regulation of obesity.

Keywords: Obesity, Animal model, Gastric bypass, Ghrelin, Peptide YY

Figures and Tables

Fig. 1
Completed Roux-en-Y gastric bypass. Gastrojejunostomy (big arrow) and jejunojejunostomy (small arrow) are shown.
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Fig. 2
Schematic figure of Roux-en-Y gastric bypass. The biliopancreatic limb from Treitz ligament is about 16 cm in length and the alimentary limb, about 10 cm in length.
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Fig. 3
Completed sleeve gastrectomy.
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Fig. 4
Weight changes expressed as percentage of weight loss. From postoperative day 7 on, Roux-en-Y gastric bypass (RYGB) group achieved significant weight loss comparing to sleeve gastrectomy (SG) and Sham operated (Sham) groups. *P<0.05.
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Fig. 5
Pre- and postoperative ghrelin levels. The decrease of ghrelin level in Roux-en-Y gastric bypass (RYGB) group was significant, while in sleeve gastrectomy (SG) and Sham operated (Sham) groups was not significant. *P=0.028.
jkss-79-155-g005
Fig. 6
Pre- and postoperative PYY3-36 levels. The increase of PYY3-36 level in Roux-en-Y gastric bypass (RYGB) group was significant, as well as in sleeve gastrectomy (SG) and Sham operated (Sham) groups. *P<0.05.
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