Effect of nifedipine on lithium-pilocarpine-induced seizures in the rats

Recent studies have shown that lithium pretreatment of rats potentiates the convulsant effect of pilocarpine. A large body of evidence support the hypothesis that calcium channel antagonists possess antiepileptic properties in various models of epilepsy. This study was designed to investigate effect of calcium channel antagonist, nifedipine on lithium-pilocarpine-induced convulsions in rats. Pretreatment of rats with nifedipine (5 or 10 mg/kg) as well as with a calcium channel agonist BAY k-8644 (2 mg/kg) increased convulsant effect induced by lithium and pilocarpine. The facilitating effect of nifedipine on lithium-pilocarpine-induced convulsions was prevented by pretreatment with a cholinergic antagonist atropine. It can be concluded that nifedipine facilitates convulsions in lithium-pilocarpine model of epilepsy and that cholinergic system may be involved in this effect.