title: The uncoupling effect of the nonsteroidal anti-inflammatory drug nimesulide in liver mitochondria from adjuvant-induced arthritic rats.
abstract: The aim of the present study was to evaluate the changes caused by adjuvant-induced arthritis in liver mitochondria and to investigate the effects of the nonsteroidal anti-inflammatory drug nimesulide. The main alterations observed in liver mitochondria from arthritic rats were: higher rates of state IV and state III respiration with beta-hydroxybutyrate as substrate; reduced respiratory control ratio and impaired capacity for swelling dependent on beta-hydroxybutyrate oxidation. No alterations were found in the activities of NADH oxidase and ATPase. Nimesulide produced: (1) stimulation of state IV respiration; (2) decrease in the ADP/O ratio and in the respiratory control ratio; (3) stimulation of ATPase activity of intact mitochondria; (4) inhibition of swelling driven by the oxidation of beta-hydroxybutyrate; (5) induction of passive swelling due to NH(3)/NH(4)+ redistribution. The activity of NADH oxidase was insensitive to nimesulide. Mitochondria from arthritic rats showed higher sensitivity to nimesulide regarding respiratory activity. The results of this work allow us to conclude that adjuvant-induced arthritis leads to quantitative changes in some mitochondrial functions and in the sensitivity to nimesulide. Direct evidence that nimesulide acts as an uncoupler was also presented. Since nimesulide was active in liver mitochondria at therapeutic levels, the impairment of energy metabolism could lead to disturbances in the liver responses to inflammation, a fact that should be considered in therapeutic intervention.
authors.affiliation: Laboratory of Biological Oxidations, Department of Biochemistry, University of Maringá, 87020900 Maringá, Brazil.
authors.forename: S M
authors.initials: SM
authors.lastname: Caparroz-Assef
authors.forename: C L
authors.initials: CL
authors.lastname: Salgueiro-Pagadigorria
authors.forename: C A
authors.initials: CA
authors.lastname: Bersani-Amado
authors.forename: A
authors.initials: A
authors.lastname: Bracht
authors.forename: A M
authors.initials: AM
authors.lastname: Kelmer-Bracht
authors.forename: E L
authors.initials: EL
authors.lastname: Ishii-Iwamoto
mesh_terms: D000251:Adenosine Triphosphatases / Q000187:drug effects / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D008565:Membrane Proteins / Q000187:drug effects / Q000378:metabolism; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D009097:Multienzyme Complexes / Q000187:drug effects / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000187:drug effects / Q000378:metabolism; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D011048:Polarography; D051381:Rats; D017208:Rats, Wistar; D013449:Sulfonamides / Q000494:pharmacology*; D014475:Uncoupling Agents / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D008565:Membrane Proteins; D009097:Multienzyme Complexes; D013449:Sulfonamides; D014475:Uncoupling Agents; D000255:Adenosine Triphosphate; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D000251:Adenosine Triphosphatases; C012655:nimesulide