Inhibition of Na(+),K(+)-ATPase activity in hippocampus of rats subjected to acute administration of homocysteine is prevented by vitamins E and C treatment.
In the present study we evaluated the effect of acute homocysteine (Hcy) administration on Na(+),K(+)-ATPase activity, as well as on some parameters of oxidative stress such as total radical-trapping antioxidant potential (TRAP) and on activities of antioxidant enzymes catalase (CAT), superoxide dismutase and glutathione peroxidase in rat hippocampus. Results showed that Hcy significantly decreased TRAP, Na(+),K(+)-ATPase and CAT activities, without affecting the activities of superoxide dismutase and glutathione peroxidase. We also verified the effect of chronic pretreatment with vitamins E and C on the reduction of TRAP, Na(+),K(+)-ATPase and CAT activities caused by Hcy. Vitamins E and C per se did not alter these parameters, but prevented the reduction of TRAP, Na(+),K(+)-ATPase and CAT activities caused by Hcy. Our results indicate that oxidative stress is probably involved in the pathogenesis of homocystinuria and that reduction of Na(+),K(+)-ATPase activity may be related to the neuronal dysfunction found in homocystinuric patients.
Wyse
Angela T S
AT
Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. wyse@ufrgs.br
Zugno
Alexandra I
AI
Streck
Emilio L
EL
Matté
Cristiane
C
Calcagnotto
Thiago
T
Wannmacher
Clovis M D
CM
Wajner
Moacir
M
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology; D006710:Homocysteine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013482:Superoxide Dismutase / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology*
D006710:Homocysteine; D014810:Vitamin E; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D000254:Sodium-Potassium-Exchanging ATPase; D001205:Ascorbic Acid