Effects of iloprost, prostaglandin E1 (PGE1) and prostacyclin (PGI2) on chemically and electrically induced seizures in mice.

The effects of iloprost (ZK 36,374), a new chemically stable analogue of prostacyclin (PGI2), on strychnine-, pentylene-tetrazol-, and maximal electroshock-induced seizures were studied in mice. The time from the beginning of the injection of the convulsant or inducing electroshock to the stage of persistent seizures was determined, and lack of tonic hindlimb extension was regarded as inhibition of convulsions. In doses of 8 micrograms--16 micrograms kg-1 iloprost already exhibited an anticonvulsant action by markedly reducing the incidence of seizures and mortality following strychnine, pentylenetetrazol or maximal electroshock. The onset of tonic seizures was also reduced by iloprost. PGE1 and PGI2 were generally effective in 7 to 13 times higher doses than iloprost. It is suggested that the anticonvulsant activity of iloprost, PGE1 and PGI2 might involve a common basic mechanism. Due to its efficacy, iloprost is a useful tool in the investigation of the anticonvulsant action of prostaglandins.