Release of monoamines from striatal slices by phenelzine and beta-phenylethylamine

Slices of striatum obtained from control rats were incubated with 3H-serotonin (3H-5HT) or 14C-dopamine (14C-DA) in the presence of pargyline; then, they were subjected to a rapid transfer technique during which they were washed either with a normal Krebs buffer or one containing known quantities of phenelzine (PEH) or beta-phenylethylamine (PE). Both PEH and PE were able to stimulate releases of 3H-5HT and 14C-DA that were greater than control. More 14C-DA than 3H-5HT was released by both compounds. Much lower concentrations of PE than of PEH were required to stimulate monoamine release. Other rats were injected intraperitoneally with behaviourally effective doses of either PEH or PE and were killed at various times. The concentrations of PEH or of PE in the striata of these animals were very high 15 min after I.P. injection, but declined rapidly thereafter. These results may be interpreted to suggest that after I.P. injection, sufficient levels of PEH and PE were attained in the rat striatum to stimulate release of endogenous 5HT and DA.