Alpha-tocopherol and ascorbic acid administration prevents the impairment of brain energy metabolism of hyperargininemic rats.
1. We have previously demonstrated that arginine administration induces oxidative stress and compromises energy metabolism in rat hippocampus. In the present study we initially investigated the influence of pretreatment with alpha-tocopherol and ascorbic acid on the effects produced by arginine on hippocampus energy metabolism. We also tested the effect of acute administration of arginine on various parameters of energy metabolism, namely glucose uptake, lactate release and on the activities of succinate dehydrogenase, complex II and cytochrome c oxidase in rat cerebellum, as well as the influence of pretreatment with alpha-tocopherol and ascorbic acid on the effects elicited by arginine on this structure. 2. Sixty-day-old female Wistar rats were treated with a single i.p. injection of saline (control) or arginine (0.8 g/kg) and were killed 1 h later. In another set of experiments, the animals were pretreated for 1 week with daily i.p. administration of saline (control) or alpha-tocopherol (40 mg/kg) and ascorbic acid (100 mg/kg). Twelve hours after the last injection of the antioxidants the rats received one i.p. injection of arginine (0.8 g/kg) or saline and were killed 1 h later. 3. Results showed that arginine administration significantly increased lactate release and diminished glucose uptake and the activities of succinate dehydrogenase and complex II in rat cerebellum. In contrast, complex IV (cytochrome c oxidase) activity was not changed by this amino acid. Furthermore, pretreatment with alpha-tocopherol and ascorbic acid prevented the impairment of energy metabolism caused by hyperargininemia in cerebellum and hippocampus of rats.
Delwing
Débora
D
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, Brazil.
Tagliari
Bárbara
B
Chiarani
Fábria
F
Wannmacher
Clovis M D
CM
Wajner
Moacir
M
Wyse
Angela Terezinha  de Souza
AT
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D042963:Electron Transport Complex II / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects*; D005260:Female; D005947:Glucose / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D020162:Hyperargininemia / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013385:Succinate Dehydrogenase / Q000378:metabolism; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000494:pharmacology*
D000975:Antioxidants; D019344:Lactic Acid; D001120:Arginine; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D003576:Electron Transport Complex IV; D024502:alpha-Tocopherol; D005947:Glucose; D001205:Ascorbic Acid