Neuroprotective effects of early vs. late administration of dantrolene in experimental status epilepticus.

We examined the effects of dantrolene, an inhibitor of intracellular calcium release, on hippocampal neuronal damage associated with 140 min of limbic status epilepticus in the rat. Dantrolene (10 mg/kg i.p.) was administered after either 30 min or 140 min of status epilepticus. Early administration was associated with a significant reduction in the amount of neuronal injury in all hippocampal subregions, while late administration was associated with less neuronal injury in area CA3 only. These findings suggest that a substantial portion of seizure-induced hippocampal injury is associated with release of calcium from intracellular stores, and that early administration of dantrolene may be a useful adjunct to anticonvulsant treatment of status epilepticus.