Comparison of the brain levels of N,N-dimethyltryptamine and alpha, alpha, beta, beta-tetradeutero-N-N-dimethyltryptamine following intraperitoneal injection. The in vivo kinetic isotope effect.

A comparison of the brain levels (microgram/g wet weight of tissue) of the hallucinogen N,N-dimethyltryptamine (DMT) and its deuterated analog alpha, alpha, beta, beta-tetradeutero-DMT (D4DMT) as a function of time and dose is reported. It was observed that the presence of deuterium in the alpha- and beta-positions of the ethylamine side-chain led to a potentiation of the level of DMT in brain. Strikingly different dynamics of uptake and clearance were also noted. We propose that these results are due to primary kinetic isotope effect, illustrating the importance of the alpha-position in the metabolism of DMT.