Inhibitory effect of 5-methoxy-N,N-dimethyltryptamine on the synaptosomal uptake of 5-hydroxytryptamine.

5-Methoxy-N,N-dimethyltryptamine (5-MeODMT) in concentrations of 0.5-500 microM produced a significant inhibition of [14C]5-hydroxytryptamine [14C]5-HT) uptake in striatal, hippocampal and hypothalamic crude synaptosomes from rat brain. Higher concentrations of 5-MeODMT (10 microM) also inhibited the uptake of [3H]dopamine [3H]DA) and induced the release of [14C]5-HT and [3H]DA from preloaded synaptosomes. It appears that the 5-HT agonist properties of 5-MeODMT may involve reuptake inhibition in addition to the previously documented direct receptor stimulation.