PROCONVULSANT AND ANTICONVULSANT EFFECTS OF EVANS BLUE-DYE IN RODENTS

THE effect of i.c.v. administration of Evans blue to sound sensitive D BA/2 mice and to genetically epilepsy-prone rats was studied. In mice, Evans blue (3.3-52 nmol) induced: hyperlocomotion, wild running, scra tching, clonic muscle spasms, tonic seizure (latency 10-45 min), follo wed by death or recovery. The CD50 value for clonic seizures for Evans blue was 35 (23-53) nmol. Pretreatment (45 min) with Evans blue (13-5 2 nmol, i.c.v.) dose-dependently reduced the incidence of sound-induce d seizures in DBA/2 mice (ED50 value against clonic seizures = 30 [15- 58] nmol, i.c.v). In rats, Evans blue (104 nmol, i.c.v.) induced elect roencephalographic seizures in the hippocampus and cortex and behaviou ral limbic seizures with a latency of 15-20 min. A reduction in the me an score (from 5 to 2-3) for behavioural seizures was observed which l asted for 4-5 days in rats electrically-kindled daily in the hippocamp al CA, subsector. Sound-induced clonic seizures in kindled and non-kin dled rats were reduced for 3-4 days after administration of Evans blue (104 nmol, i.c.v.).