Inhibition of constriction of cerebral arterioles in vivo by naftidrofuryl. Action against serotonin and dinoprost.

The effect of 2-(diethylamino) ethyl-tetrahydro-alpha-(1-naphthyl-methyl)-2-furanpropionate (naftidrofuryl, Praxilene) on an in vivo preparation of mouse cerebral blood vessels was investigated. Naftidrofuryl significantly reduced the arteriolar constriction produced by topical application of serotonin or dinoprost (prostaglandin F2 alpha). Local application of 10(-5) mol/l naftidrofuryl reduced both the constrictions to serotonin or dinoprost, when applied simultaneously with either constrictor. However, 10(-7) mol/l naftidrofuryl only inhibited serotonin. Moreover, 30 min after intraperitoneal injection, 160 mg/kg naftidrofuryl inhibited constrictions by either serotonin or dinoprost but 40 mg/kg only inhibited serotonin. 10 mg/kg also inhibited serotonin. The results are compatible with reports of a relatively selective action of naftidrofuryl on the serotonin S2 receptor. Moreover, while naftidrofuryl has long been suggested as a drug which could enhance cerebral blood flow or improve cerebral ischemia, the present observations suggest an antispasmodic effect on cerebral vessels in vivo.