Effects of lisuride and quinpirole on convulsions induced by hyperbaric oxygen in the mouse

Two ergot derivatives, lisuride and quinpirole, were examined for their ability to antagonize hyperbaric oxygen-induced (5 ATA O2) convulsions in mice. Significant protection was obtained by lisuride (25-400 micrograms.kg-1, i.p.) and quinpirole (100-200 micrograms.kg-1, i.p.). The efficacy was found to be about 50% of the protection obtained by diazepam (4 mg.kg-1, i.p.). Both lisuride and quinpirole significantly reduced rectal temperature at all doses administered. In separate experiments, at normal atmospheric conditions, all drugs to some extent reduced estimated respiratory minute volume. Taking these effects into account, lisuride is considerably more active as an anticonvulsant than quinpirole.