The Role of nitric oxide in convulsions induced by lindane in rats

Lindane is an organochloride pesticide and scabicide. It evokes convulsions mainly trough the blockage of GABA A receptors. Nitric oxide (NO), gaseous neurotransmitter, has contradictor role in epileptogenesis due to opposite effects of l-arginine, precursor of NO syntheses (NOS), and L-NAME (NOS inhibitor) observed in different epilepsy models. The aim of the current study was to determine the effects of NO on the behavioral and EEG characteristics of lindane-induced epilepsy in male Wistar albino rats. The administration of l-arginine (600, 800 and 1000 mg/kg, i.p.) in dose-dependent manner significantly increased convulsion incidence and severity and shortened latency time to first convulsion elicited by lower lindane dose (4 mg/kg, i.p.). On the contrary, pretreatment with L-NAME (500, 700 and 900 mg/kg, i.p.) decreased convulsion incidence and severity and prolonged latency time to convulsion following injection with a convulsive dose of lindane (8 mg/kg, i.p.). EEG analyses showed increase of number and duration of ictal periods in EEG of rats receiving l-arginine prior to lindane and decrease of this number in rats pretreated with L-NAME. These results support the conclusion that NO plays a role of endogenous convulsant in rat model of lindane seizures.