title: Inhibition of CO(2) production from glucose by arginine in brain slices of rats.
abstract: In the present study we evaluated the in vivo effect of arginine on CO(2) production from glucose in a medium with physiological and high extracellular K(+) concentrations. We also tested the influence of the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), on the effects elicited by arginine in order to investigate the possible participation of NO and/or its derivatives on the effects of arginine on CO(2) production from glucose. Sixty-day-old rats were treated with a single intraperitoneal injection of saline (control; group I), arginine (0.8 g/kg; group II), L-NAME (2.0 mg/kg; group III) or arginine (0.8 g/kg) plus L-NAME (2.0 mg/kg; group IV) and were killed 1 h later. Results showed that arginine administration inhibited CO(2) production from glucose at physiological extracellular K(+) concentration and L-NAME prevented such effect. In contrast, arginine administration had no effect on CO(2) production from glucose at high extracellular K(+) concentration. Based on these data, we also investigated the in vitro effect of arginine on CO(2) production from glucose in a medium with physiological extracellular K(+) concentration in hippocampus slices. Results showed that arginine (0.1-1.5 mM) when added to the incubation medium did not alter CO(2) production from glucose in hippocampus slices of untreated rats. In addition, we also demonstrated that arginine inhibits Na(+), K(+)-ATPase activity. The data indicate that the reduction of CO(2) production by arginine was probably mediated by NO and/or its derivatives, which could act inhibiting the activity of Na(+), K(+)-ATPase. The results suggest that arginine impairs energy metabolism in hippocampus slices of rats.
authors.affiliation: Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Débora
authors.initials: D
authors.lastname: Delwing
authors.forename: Francieli M
authors.initials: FM
authors.lastname: Stefanello
authors.forename: Marcos L S
authors.initials: ML
authors.lastname: Perry
authors.forename: Angela T S
authors.initials: AT
authors.lastname: Wyse
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001921:Brain / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
chemical_list: D002245:Carbon Dioxide; D009569:Nitric Oxide; D001120:Arginine; D000254:Sodium-Potassium-Exchanging ATPase; D005947:Glucose; D019331:NG-Nitroarginine Methyl Ester