Effects of amphetamine derivatives on brain dopamine and noradrenaline

Abstract

1 . Intracisternally administered metaraminol, α-methyl-octopamine, α-methyl-m-tyramine, and α-methyl tyramine were found to lower brain noradrenaline without having an effect on brain dopamine. 2 . Amphetamine, mephentermine, and norephedrine had no effect on brain catecholamines after intracisternal injection. 3 . There was no reduction in brain dopamine content after intracisternal injection of α-methyl-m-tyramine, yet the resulting brain concentration of α-methyl-m-tyramine was several times higher than after intraperitoneal injection of α-methyl-m-tyrosine, which decreased brain dopamine. 4 . The decreased synthesis of labelled catecholamines from ¹⁴C-tyrosine after α-methyl-m-tyrosine suggested that this compound inhibits tyrosine hydroxylase in addition to its action of displacing brain amines.