The regional distribution of p-tyramine and m-tyramine in the rat corpus striatum and the effect of monoamine oxidase inhibition.

These experiments show that in the rat corpus striatum the highest concentrations of p- and m-tyramine were found in the caudate nucleus while somewhat lower values were observed in the putamen and globus pallidus. Inhibition of monoamine oxidase by pargyline produced an increase in the concentration of both tyramines in the three areas. The effect of pargyline is more marked with p-tyramine, however, the regional distribution of both p- and m-tyramine are preserved after monoamine oxidase inhibition. In addition, the pargyline treatment produced a significant reduction in corpus striatum p-tyrosine while no changes were observed in the tryptophan concentrations.