Stimulation of Brain Dopamine Synthesis by Gamma‐hydroxybutyrate

Gamma‐hydroxybutyrate administration produces a marked selective increase of brain dopamine in different animal species. Following γ ‐hydroxybutyrate administration, dopamine accumulated in the basal ganglia of the rat and in the caudate nucleus of the rabbit at a rate which greatly exceeded the normal synthesis rate of the amine in these species. Dopamine accumulation was prevented by α ‐methyltyrosine. These data indicate that γ ‐hydroxybutyrate stimulates dopamine synthesis. In addition, γ ‐hydroxybutyrate increased the homovanillic acid level in the rat basal ganglia to a maximum of about 300 per cent of the normal level indicating that γ ‐hydroxybutyrate inhibits neither monoamine oxidase nor catechol O ‐methyltransferase in vivo. The possible mechanisms of dopamine accumulation following γ ‐hydroxybutyrate administration are discussed.