The effects of ethanol intake and withdrawal on penicillin-induced epileptiform activity in rats

Abstract

Previous experiments have shown that ethanol may have either pro-convulsive or anti-convulsive effects on epileptic activity in different experimental epilepsy models. In this study, the effect of low dose ethanol and its withdrawal on penicillin-induced epileptiform activity in rat was investigated. Eight groups of adult, male Wistar rats were studied: (1) control, (2) penicillin pretreated (500 units), (3) α-tocopherol (500 mg/kg, i.m.), (4) penicillin pretreated + α-tocopherol, (5) ethanol-treated (3 g/kg, per day, for 15 days, intragastrically) + penicillin, (6) ethanol-treated + penicillin + α-tocopherol, (7) ethanol withdrawal + penicillin, (8) ethanol withdrawal + penicillin + α-tocopherol. Each animal group was composed of seven rats. The epileptiform activity was verified by electrocorticographic (ECoG) recordings. The epileptiform activity was induced by microinjection of penicillin into the left sensorimotor cortex. Administration of ethanol (3 g/kg, per day, for 15 days, intragastrically) did not change either frequency or amplitude of penicillin-induced epileptiform activity. The frequency and amplitude of epileptiform activity were evaluated 40 h after the last ethanol administration in withdrawal groups. There was no significant change in the mean frequency and amplitude of epileptiform activity compared with penicillin pretreated and ethanol-treated groups. The effective dose of α-tocopherol (500 mg/kg, i.m.) significantly decreased the mean frequency of epileptiform activity in the 60, 70, and 120 min after α-tocopherol injection in penicillin pretreated, ethanol-treated, ethanol withdrawal groups, respectively. However, α-tocopherol did not affect the amplitude of epileptiform activity in all groups. In conclusion, the present results indicate that low dose of ethanol does not have either anticonvulsive or proconvulsive effect on penicillin-induced epileptiform activity. α-Tocopherol has anti-convulsive effect on penicillin-induced epileptiform activity in effective dose.