RESUMO
Previous studies suggest that organic solvents show anticonvulsant and convulsant effects, respectively at low and high doses. In the present study the first experiment was designed to determine low and high doses of injected acute n-hexane, ethyl acetate and toluene in mice through LD50 estimations. In the second experiment, high doses (around LD50) were employed to evaluate the convulsant effects. Finally, the third experiment evaluated the ability of low doses to prevent electroshock- and PTZ-induced convulsions. Results showed that n-hexane increased the severity of the electroshock-induced seizures only at low doses and had no anticonvulsant effects. Ethyl acetate produced generalized clonic seizures and deaths at high doses and was ineffective to prevent electroshock- and PTZ-induced seizures at low doses. Toluene induced forelimb clonus at high doses and protected against electroshock-induced seizures at low doses. Therefore, the biphasic property on convulsant activity seems to be a feature not shared among organic solvents.