title: TNF-alpha-dependent bilateral renal injury is induced by unilateral renal ischemia-reperfusion.
abstract: While tumor necrosis factor (TNF)-alpha is an important mediator of renal ischemia-reperfusion (I/R) injury, its role in contralateral renal injury after isolated renal ischemia remains unknown. We therefore investigated the effect of isolated left renal ischemia on the nonischemic contralateral kidney. To study this, male Sprague-Dawley rats were anesthetized and exposed to varying degrees of left renal I/R injury. Both kidneys were subsequently harvested, serum samples were obtained, and TNF-alpha protein expression (ELISA), TNF-alpha mRNA content (RT-PCR), TNF-alpha immunolocalization, and neutrophil infiltration (myeloperoxidase assay) were determined. The effect of TNF-alpha on neutrophil infiltration was assessed by neutralizing TNF-alpha with TNF binding protein (TNF-BP) before left renal I/R injury. TNF-alpha protein expression, TNF-alpha mRNA induction, and neutrophil infiltration increased significantly in both kidneys after unilateral renal I/R injury. Furthermore, the administration of TNF-BP before unilateral renal I/R substantially reduced the degree of neutrophil infiltration bilaterally. These results constitute the initial demonstration that unilateral renal I/R induces bilateral TNF-alpha production and neutrophil infiltration through a TNF-alpha-dependent mechanism.
authors.affiliation: Department of Urology, Johns Hopkins University, Baltimore, Maryland 21287, USA. kkmeldrum@earthlink.net
authors.forename: Kirstan K
authors.initials: KK
authors.lastname: Meldrum
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Meldrum
authors.forename: Xianzhong
authors.initials: X
authors.lastname: Meng
authors.forename: Lihua
authors.initials: L
authors.lastname: Ao
authors.forename: Alden H
authors.initials: AH
authors.lastname: Harken
mesh_terms: D000818:Animals; D001794:Blood Pressure; D005786:Gene Expression Regulation / Q000276:immunology; D007668:Kidney / Q000276:immunology / Q000503:physiopathology; D007674:Kidney Diseases / Q000276:immunology* / Q000503:physiopathology*; D008297:Male; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism; D010100:Oxygen / Q000097:blood; D009195:Peroxidase / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I; D015427:Reperfusion Injury / Q000276:immunology* / Q000503:physiopathology*; D053319:Tumor Necrosis Factor Decoy Receptors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D053319:Tumor Necrosis Factor Decoy Receptors; D014409:Tumor Necrosis Factor-alpha; C069521:recombinant human tumor necrosis factor-binding protein-1; D009195:Peroxidase; D010100:Oxygen