11C-labeling of indolealkylamine alkaloids and the comparative study of their tissue distributions.
The International journal of applied radiation and isotopes – December 01, 1985
Source: PubMed
Summary
The compound [11C]DMT stands out as a promising radiopharmaceutical for studying serotonin mechanisms in the brain, achieving a remarkable radiochemical yield of 50% and high brain uptake. In tests involving rats, labeled compounds showed significant accumulation in key organs: the liver, lung, and small intestine. Notably, [11C]DMT and [11C]OMB demonstrated substantial retention in the brain, while other tested radiopharmaceuticals exhibited low brain uptake. Overall, [11C]DMT's superior properties position it as a leading candidate for neuropharmacological studies.
Abstract
Five indolealkylamines (N,N-dimethyltryptamine, N-methyltryptamine, bufotenine, O-methylbufotenine, N,N,N-trimethyltryptamine iodide) were labeled with 11C by use of 11CH3I. The labeled compounds were synthesized with a radiochemical yield of 2-50% (based on trapped 11CH3I) in 20-35 min with radiochemical purities of more than 92%. The tissue distributions of these labeled compounds were investigated in rats. In all cases, the accumulations in the liver, lung and small intestine were high. [11C]DMT and [11C]OMB also accumulated to a large extent in the brain, where their accumulation was retained. Brain uptake of three other radiopharmaceuticals was low. [11C]DMT is the radiopharmaceutical of choice for the study of the serotonin action mechanism in the brain, because it has the highest radiochemical yield and the highest brain uptake of these 11C-labeled compounds.