title: Effect of lead acetate on cytosolic thioredoxin reductase activity and oxidative stress parameters in rat kidneys.
abstract: Oxidative stress has been suggested to be an important molecular mechanism of toxic effects of lead in the kidney. Thioredoxin reductase-1 is a selenoprotein involved in many cellular redox processes. This study evaluated the effect of acute and chronic exposure intraperitoneally to lead acetate on thioredoxin reductase-1 activity and on other oxidative stress parameters in the rat kidney, as well as on indicators of renal function commonly used to assess lead poisoning. Acute exposure to 25 mg/kg lead acetate increased superoxide dismutase and thioredoxin reductase-1 activity (after 6, 24 and 48 hr), while exposure to 50 mg/kg lead acetate increased catalase activity (after 48 hr) and inhibited delta-aminolevulinate dehydratase activity (after 6, 24 and 48 hr) in the kidney (P < 0.05). Chronic exposure (30 days) to 5 mg/kg lead acetate inhibited delta-aminolevulinate dehydratase and increased glutathione S-transferase, non-protein thiol groups, catalase, thioredoxin reductase-1 and uric acid plasma levels, while exposure to 25 mg/kg lead acetate reduced body weight and delta-aminolevulinate dehydratase, but increased glutathione S-transferase, non-protein thiol groups and uric acid plasma levels (P < 0.05). No changes were observed in thiobarbituric acid reactive substances, glutathione peroxidase, creatinine or inorganic phosphate levels after either acute or chronic exposure. Our results suggest that thioredoxin reductase-1 may be an early indicator of acute exposure to low lead doses.
authors.affiliation: Postgraduate Program on Biochemical Toxicology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: Greicy M M
authors.initials: GM
authors.lastname: Conterato
authors.forename: Paula R
authors.initials: PR
authors.lastname: Augusti
authors.forename: Sabrina
authors.initials: S
authors.lastname: Somacal
authors.forename: Lídia
authors.initials: L
authors.lastname: Einsfeld
authors.forename: Rocheli
authors.initials: R
authors.lastname: Sobieski
authors.forename: Juliana R V
authors.initials: JR
authors.lastname: Torres
authors.forename: Tatiana
authors.initials: T
authors.lastname: Emanuelli
mesh_terms: D000818:Animals; D003404:Creatinine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D007668:Kidney / Q000187:drug effects* / Q000201:enzymology; D007677:Kidney Function Tests; D008297:Male; D009942:Organometallic Compounds / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D000623:Porphobilinogen Synthase / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D054481:Thioredoxin Reductase 1; D013880:Thioredoxin-Disulfide Reductase / Q000187:drug effects* / Q000378:metabolism; D014527:Uric Acid / Q000097:blood
chemical_list: D009942:Organometallic Compounds; D014527:Uric Acid; D003404:Creatinine; D054481:Thioredoxin Reductase 1; D013880:Thioredoxin-Disulfide Reductase; C516126:Txnrd1 protein, rat; D000623:Porphobilinogen Synthase; C008261:lead acetate