Long-lasting psychodysleptic N,N-dimethyltryptamine in brain by gamma-emitter studies: Comparison with tryptamine and serotonin

ARTURO A. VITALE; ALICIA B. POMILIO; CARLOS O. CAÑELLAS; NORBERTO JORGE MACARENO; DOMINIQUE ZÜRCHER; EVA MARIA PUTZ; JORGE CIPRIAN-OLLIVIER

JOURNAL OF NEUROCHEMISTRY

Wiley-Blackwell

Año: 2008

0022-3042

Single photon emission computed tomography (SPECT)/gamma-camera studies of [131I]-2- iodo-N,N-dimethyltryptamine ([131I]-DMT), [131I]-2-iodotryptamine ([131I]-T) and [131I]-2- iodo-5-hydroxytryptamine or [131I]-2-iodoserotonin ([131I]-5-HT) were carried out in rabbits. Images were acquired every 30 seconds until 60 minutes, and then at 120, 180, 240 and 360 minutes, extended upto 48 hours. Brain, heart, liver, kidneys and bladder were the regions of interest (ROIs). Brain uptake, plasma clearance, and renal excretion were assessed. Brain uptake of [131I]-DMT accounted for 20.0 ± 2.2 % injected dose (ID) after 5 minutes, then being efficiently excreted, remaining 2.1% after 60 minutes. An amount of 70.1 ± 5.5 % ID of [131I]-DMT was uptaken by bladder after 60 min. The fact that 2.1 ± 0.5% ID of [131I]-DMT was retained in brain after 60 min, and that the labelled DMT was kept in brain two days after injection was shown for the first time, thus indicating a differential behaviour of this compound in relation with both serotonin and tryptamine. Discussion of this DMT behaviour includes the 5-HT2A agonistic activity of DMT, together with the activity at the trace amineassociated receptors (TAARs).