RESUMO
The influence of lithium chloride on the anticonvulsant activity of sodium valproate [VAL] was evaluated against two chemically-induced convulsive seizures; namely, bicuculline [BIC] and kainic acid [KAA]. Both drugs were given i.p., either singly or in combination to groups of mice [n = 8] and were allowed to act for 30 minutes before the chemical induction of seizures. Valproate was used in doses of 200 and 300 mg/kg [its ED50 against the specific convulsive agent] against BIC and KAA, respectively, whereas lithium chloride was used in a dose of 10 mg/kg. Then, convulsions were induced by i.p. injection of kainic acid [KAA, 70 mg/kg] and bicuculline [BIC, 1 mg/kg]. The animals were observed over a period of 40 minutes for the onset of convulsions. The mean survival time [MST] and the percentage of animals protected from death produced by each convulsive agent were computed. In conclusion, the present study suggested that the anticonvulsant action of sodium valproate against BIC and KAA-induced seizures may be partially augmented by the concurrent use of lithium chloride and this could be explained, at least in part, by the effect of lithium on the electrolyte levels caused by valproate