Protective effect of antioxidants on blood oxidative stress caused by arginine

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In this study, we investigated in vivo and in vitro effect of arginine on parameters of oxidative stress namely thiobarbituric acid-reactive substances (TBA-RS) and total radical-trapping antioxidant parameter (TRAP) in plasma and on the antioxidant enzymes activities catalase (CAT), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) in erythrocytes of rats. Results showed that acute administration reduced TRAP and CAT activity and increased TBA-RS. Furthermore, in vitro studies did not alter oxidative parameters studied. The influence of N?-nitro-l-arginine methyl ester (l-NAME) and antioxidants (a-tocopherol plus ascorbic acid) on the effects elicited by arginine was also studied. In addition, simultaneous injection of l-NAME or treatment with antioxidants prevented the alteration on TRAP, TBA-RS, and CAT activity caused by arginine. Data indicate that oxidative stress induction is probably mediated by the generation of NO and/or ONOO- and other free radicals, because l-NAME and these antioxidants prevented these effects caused by arginine.262250258Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq