Effect of lead acetate on cytosolic thioredoxin reductase activity and oxidative stress parameters in rat kidneys.
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.
Conterato
Greicy M M
GM
Postgraduate Program on Biochemical Toxicology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
Augusti
Paula R
PR
Somacal
Sabrina
S
Einsfeld
Lídia
L
Sobieski
Rocheli
R
Torres
Juliana R V
JR
Emanuelli
Tatiana
T
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
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