The selective PPARgamma antagonist GW9662 reverses the protection of LPS in a model of renal ischemia-reperfusion.

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.

• Authors: Massimo Collino, Nimesh S A Patel, Kevin M Lawrence, Marika Collin, David S Latchman, Muhammad M Yaqoob, Christoph Thiemermann
• Journal: Kidney international (Kidney Int) Vol. 68 Issue 2 Pg. 529-36 (Aug 2005) ISSN: 0085-2538 [Print] United States
• PMID: 16014029 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

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