Roux-en-Y gastric bypass alters tumor necrosis factor-α but not adiponectin signaling in immediate postoperative period in obese rats

Rideout, Drew A.; Peng, Yanhua; Rakita, Steven S.; Desai, Karan; Gower, William R.; You, Min; Murr, Michel M.

doi:10.1016/j.soard.2010.05.017

« Previous Next »Surgery for Obesity and Related Diseases
Volume 6, Issue 6 , Pages 676-680, November 2010

Roux-en-Y gastric bypass alters tumor necrosis factor-α but not adiponectin signaling in immediate postoperative period in obese rats

Presented at the Plenary Session of the 2009 American Society for Metabolic and Bariatric Surgery Annual Meeting, Grapevine, Texas

Drew A. Rideout, M.D.
- Department of Surgery, James A. Haley Veterans Affairs Medical Center, University of South Florida, Tampa, Florida
Yanhua Peng, Ph.D.
- Department of Surgery, James A. Haley Veterans Affairs Medical Center, University of South Florida, Tampa, Florida
Steven S. Rakita, M.D.
- Department of Surgery, James A. Haley Veterans Affairs Medical Center, University of South Florida, Tampa, Florida
Karan Desai, B.S.
- Department of Surgery, James A. Haley Veterans Affairs Medical Center, University of South Florida, Tampa, Florida
William R. Gower Jr, Ph.D.
- Department of Research, University of South Florida, Tampa, Florida
Min You, Ph.D.
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
Michel M. Murr, M.D., F.A.C.S.
- Department of Surgery, James A. Haley Veterans Affairs Medical Center, University of South Florida, Tampa, Florida
- Correspondence: Michel M. Murr, M.D., F.A.C.S., University of South Florida c/o Tampa General Hospital, P.O. Box 1289, Tampa, FL 33601

Received 10 November 2009; received in revised form 20 April 2010; accepted 23 May 2010. published online 09 June 2010.

Abstract

Background

Adiponectin has anti-inflammatory properties and is increased with weight loss. Tumor necrosis factor (TNF)-α is a pro-inflammatory cytokine that negatively regulates adiponectin. Previously, we have demonstrated that Roux-en-Y gastric bypass (RYGB) induces weight loss and improves steatosis in obese rats. We hypothesized that RYGB would alter the interplay of TNF-α and adiponectin signaling in the postoperative period.

Methods

Obese Sprague-Dawley male rats that had undergone RYGB (n = 5) or sham (n = 4) were euthanatized at 9 weeks postoperatively. The adiponectin levels from serial serum samples were measured by enzyme-linked immunosorbent assay. Adiponectin, adiponectin receptor 2, and TNF-α mRNA from adipose and liver samples were quantified by reverse transcriptase-polymerase chain reaction. Data are presented as mean ± standard deviation; using a t test, P <.05 was significant.

Results

RYGB did not change the serum adiponectin, adipose tissue adiponectin mRNA, or hepatic adiponectin receptor 2 levels compared with the levels in the sham-operated rats (P >.05). However, the TNF-α mRNA levels had decreased in the adipose tissue (P >.05) but remained unchanged in the liver compared with the sham controls (P >.05).

Conclusion

Surgically-induced weight loss in a rat model of RYGB did not increase adiponectin signaling in the immediate postoperative period but was associated with decreased pro-inflammatory signaling in the adipose tissue. During this period, pro-inflammatory signaling might play a more important role than adiponectin. Additional studies with longer follow-up are necessary to determine whether adiponectin plays a role in weight loss and improvement of steatosis after RYGB.

Keywords: Obesity, Gastric bypass, Rat, Adiponectin, Tumor necrosis factor-α, TNF-α, Inflammation