The effects of beta-phenylethylamine on tyramine and dopamine metabolism.

The administration of deuterated beta-phenylethylamine to mice causes increased concentrations of deuterated para-hydroxyphenylacetic acid and meta-hydroxyphenylacetic acid within the caudate nuclei two hours after injection. Deuterated m-HPAA concentrations remain elevated at 4 hours. This suggests that high concentrations of PE stimulate synthesis of the tyramines and thus of their deaminated metabolites. Deuterated PE causes rapid increases in the concentrations of endogenous nondeuterated p-HPAA and m-HPAA. p-HPAA concentrations remain elevated two hours after PE administration. Thus PE mobilizes the tyramines and produces elevated concentrations of their deaminated products. PE injected into rats initially increases 3-MT concentrations in the caudate nuclei. DOPAC concentrations are elevated five minutes later followed by elevated HVA concentrations. DA synthesis is also stimulated. The PE dependent increase in DA release into the synaptic cleft (3-MT increases) and DA synthesis also appear to lead to increased intraneuronal DA metabolism (DOPAC increases).