Prostaglandin E1-induced potentiation of the anticonvulsant action of phenobarbitone in the rat. Role of brain monoamines.

Prostaglandin E1 (PGE1) significantly potentiated the anticonvulsant action of a sub-effective (EDO) dose of phenobarbitone, against maximal electroshock-induced seizures in the rat. PGE1-induced potentiation of phenobarbitone was significantly inhibited after pretreatment with drugs which are known to reduce brain serotonin activity, but was unaffected by drugs known to decrease brain catecholamine activity. Prostaglandin F2 alpha produced a moderate though statistically insignificant inhibition of PGE1 effect. The results suggest that PGE1-induced potentiation of phenobarbitone is not a direct effect but an indirect one, mediated through an increase in brain serotonin activity.