The Selective PPARgamma Antagonist GW9662 Reverses the Protection of LPS in a Model of Renal Ischemia-Reperfusion

Kidney Int. 2005 Aug;68(2):529-36. doi: 10.1111/j.1523-1755.2005.00430.x.

Abstract

Background: We have recently reported that pretreatment of rats with endotoxin (lipopolysaccharide, LPS) and selective agonists of the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARgamma) protect the kidney against ischemia/reperfusion (I/R) injury. Here we investigate the hypothesis that the renoprotective effects of LPS may be due to an enhanced formation of endogenous ligands of PPARgamma, rather than an up-regulation of PPARgamma expression.

Methods: Rats were pretreated with LPS (1 mg/kg, IP, 24 hours prior to ischemia) in the absence (control) or presence of the selective PPARgamma antagonist GW9662 (1 mg/kg, IP, 24 and 12 hours prior to ischemia). Twenty-four hours after injection of LPS, rats were subjected to 60 minutes of bilateral renal ischemia, followed by 6 hours of reperfusion. Serum and urinary indicators of renal injury and dysfunction were measured, specifically serum creatinine, aspartate aminotransferase, and gamma-glutamyl-transferase, creatinine clearance, urine flow, and fractional excretion of sodium. Kidney PPARgamma1 mRNA levels were determined by reverse transcriptase-polymerase chain reaction.

Results: Pretreatment with LPS significantly attenuated all markers of renal injury and dysfunction caused by I/R. Most notably, GW9662 abolished the protective effects of LPS. Additionally, I/R caused an up-regulation of kidney PPARgamma1 mRNA levels compared to sham animals, which were unchanged in rats pretreated with LPS.

Conclusion: We document here for the first time that endogenous ligands of PPARgamma may contribute to the protection against renal I/R injury afforded by LPS pretreatment in the rat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anilides / pharmacology*
  • Animals
  • Drug Interactions
  • Kidney Diseases / drug therapy*
  • Kidney Diseases / physiopathology
  • Lipopolysaccharides / pharmacology*
  • Male
  • PPAR gamma / antagonists & inhibitors*
  • PPAR gamma / genetics
  • RNA, Messenger / analysis
  • Rats
  • Rats, Wistar
  • Reperfusion Injury / drug therapy*
  • Reperfusion Injury / physiopathology

Substances

  • 2-chloro-5-nitrobenzanilide
  • Anilides
  • Lipopolysaccharides
  • PPAR gamma
  • RNA, Messenger