Abstract

The present study reports the distribution and metabolism of 3,4-dimethoxyphenylethylamine-¹⁴C (DMPEA-¹⁴C) in rabbit brain one hour after the i.v. administration of the radioactive compound. The ¹⁴C was unevenly distributed into various regions with the highest level in the caudate nucleus and the lowest in the superior collicuius. All 11 brain areas studied were active in oxidative deamination of injected DMPEA. The levels of total radioactivity in the caudate nucleus, inferior colliculus, thalamus and hypothalamus were about 2 to 2½ times that in the superior colliculus. The levels of unchanged amine in these areas and the medulla, as well, were significantly higher than those in the hippocampus which concentrated the lowest amount. Marked increases in the levels of unchanged DMPEA-¹⁴C were observed in almost all brain areas of rabbits pretreated with iproniazid. In animals pretreated with reserpine, the levels of total radioactivity and nondeaminated compounds were significantly increased in the superior colliculus and the thalamus. The high concentrations of DMPEA in some regions belonging to the extrapyramidal system may have significance in the DMPEA-induced akinesia.