Effects of raunescine and isoraunescine on behaviour and on the 5-hydroxytryptamine and noradrenaline contents of brain.

Some behavioural effects of raunescine and isoraunescine on pigeons have been studied; no qualitative difference was detected between their effects and those of reserpine. Isoraunescine is between five and ten times less potent than raunescine, which, in turn, is much less potent than reserpine in producing these effects.Both raunescine (5 mg./kg.) and isoraunescine (50 mg./kg.) were found to cause a reduction in the concentration of noradrenaline in the brains of rats. Raunescine (5 mg./kg.) also caused a reduction in the concentration of 5-hydroxytryptamine in brain; isoraunescine did not do so in the same dose; higher dose levels were not studied.