Arginine administration reduces catalase activity in midbrain of rats.
Hyperargininemia is an inherited neurometabolic disorder biochemically characterized by tissue accumulation of arginine and clinically by severe neurological symptoms whose pathophysiology is poorly understood. In the present study we investigated the effect of arginine administration on the antioxidant enzyme activities catalase, glutathione peroxidase and superoxide dismutase in rat midbrain. We also tested the effect of L-NAME on the effects produced by Arg. The results showed that arginine decreased catalase activity, without altering the other two activities. L-NAME had no effect on catalase activity, but prevented the reduction of this enzyme provoked by arginine, suggesting that NO formation is involved in the reduction of catalase activity caused by the amino acid. If these findings also occur in the human condition, it may be presumed that oxidative stress contributes to the brain dysfunction observed in hyperargininemia.
Delwing
Débora
D
Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003, Porto Alegre, RS, Brazil.
Delwing
Daniela
D
Dutra-Filho
Carlos S
CS
Wannmacher
Clóvis M D
CM
Wajner
Moacir
M
Wyse
Angela T S
AT
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000378:metabolism; D020162:Hyperargininemia / Q000378:metabolism; D008636:Mesencephalon / Q000187:drug effects* / Q000201:enzymology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism
D004791:Enzyme Inhibitors; D001120:Arginine; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D019331:NG-Nitroarginine Methyl Ester