The effect of ethosuximide, dipropylacetate and clonazepam on metrazol convulsions induced by a dose of 80 mg/kg was studied in 314 male albino rats aged from 5 days to adult. In a standard dose of 125 mg/kg, ethosuximide reliably protected only adult and 25-day-old rats, i.e. the age groups in which a mature minimal seizure was the only type of convulsion induced; in younger animals, not even a much higher dose (tested in 12-day-old rats) afforded reliable protection. Dipropylacetate and clonazepam had a manifest protective effect in all age groups, irrespective of the type of seizure. Isolated myoclonic jerks were less sensitive to antiepileptics and only dipropylacetate blocked them in the youngest age groups. In 21-day-old and older animals dipropylacetate induced stereotype head movement reminiscent of the serotonergic stereotypy described in the literature.

Epilepsy Research in the Institute of Physiology of the Czech Academy of Sciences in Prague

Anticonvulsant action of 2-chloroadenosine against pentetrazol-induced seizures in immature rats is due to activation of A1 adenosine receptors