title: Comparative autoradiographic and metabolic study of delta8- and delta9-tetrahydrocannabinol in the brain of the marmoset Callithrix jacchus.
abstract: The label distribution in the brain of the marmoset Callithrix jacchus following intravenous application of radioactively labeled delta8-tetrahydrocannabinol (delta8-THC) and delta9-THC is investigated by autoradiographic technique. Accumulations of label are observed in nuclei concerned with motor function, in the optic and acoustic pathways, and a few other structures. Of the two hydroxylated isomeres which were shown to be equally psychoactive the brain concentration of 11-OH-delta9-THC was found to be about 3 times higher as compared with 11-OH-delta8 THC, which may explain why delta9-THC is more potent than delta8-THC. More than 90% of the radioactivity found in the brain can be attributed to the THCs and their 11-hydroxylated isomeres. Polar metabolites are almost completely absent from the brain.
mesh_terms: D000818:Animals; D001306:Auditory Pathways / Q000378:metabolism; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D002143:Callitrichinae; D002188:Cannabis / Q000378:metabolism*; D013759:Dronabinol / Q000378:metabolism*; D000882:Haplorhini; D006900:Hydroxylation; D007536:Isomerism; D014795:Visual Pathways / Q000378:metabolism
chemical_list: D013759:Dronabinol