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C S Bavaresco

Publications and source records attributed to C S Bavaresco.

2 recordsLinked to original sources
PubMed2001

In vitro stimulation of oxidative stress in cerebral cortex of rats by the guanidino compounds accumulating in hyperargininemia.

Hyperargininemia is a metabolic disorder biochemically characterized by tissue accumulation of arginine and other guanidino compounds. Convulsions, lethargy and psychomotor delay or cognitive deterioration are predominant clinical features of this disease. Although neurologic symptoms predominate in this disorder, their pathophysiology is still unknown. In the present study we investigated the in vitro effects of arginine, N-acetylarginine, argininic acid and homoarginine on some oxidative stress parameters in rat brain in the hope to identify a possible mechanism for the brain damage in hyperargininemia. Chemiluminescence, total radical-trapping antioxidant potential (TRAP), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were measured in the cerebral cortex of rats in the presence of various concentrations of these compounds. The results showed that all guanidino compounds tested significantly increased chemiluminescence and decreased TRAP at concentrations similar to those observed in the tissue of hyperargininemic patients. Furthermore, these compounds inhibited CAT and GSH-Px activities to varying extents, with GSH-Px activity being more susceptible to their action. In turn, argininic acid inhibited all enzyme activities, and its main action was also directed towards GSH-Px. The results suggest that oxidative stress caused by guanidino compounds may be involved in the brain dysfunction amongst other potential pathophysiological mechanisms observed in hyperargininemia.

Age Factors↗
PubMed2001

Nitric oxide synthase inhibition by L-NAME prevents the decrease of Na+,K+-ATPase activity in midbrain of rats subjected to arginine administration.

In the present study we investigated the effect of acute administration of L-arginine on Na(+),K(+)-ATPase and Mg(2+)-ATPase activities and on some parameters of oxidative stress (chemiluminescence and total radical-trapping antioxidant parameter-TRAP) in midbrain of adult rats. We also tested the effect of L-NAME on the effects produced by arginine. Sixty-day-old rats were treated with an acute intraperitoneal injection of saline (group I, control), arginine (0.8 g/kg) (group II), L-NAME (2 mg/kg) (group III) or arginine (0.8 g/kg) plus L-NAME (2 mg/kg) (group IV). Na(+),K(+)-ATPase activity was significantly reduced in the arginine-treated rats, but was not affected by other treatments. In contrast, Mg(2+)-ATPase activity was not altered by any treatment. Furthermore, chemiluminescence was significantly increased and TRAP was significantly decreased in arginine-treated rats, whereas the simultaneous injection of L-NAME prevented these effects. These results demonstrate that in vivo arginine administration reduces Na(+),K(+)-ATPase activity possibly through free radical generation induced by NO formation.

Animals↗