EFFECTS OF SOME HALLUCINOGENIC DRUGS UPON METABOLISM OF 5-HYDROXY-TRYPTAMINE IN BRAIN

The effects of the four hallucinogenic drugs (phencyclidine, Ditran, LSD-25 and mescaline) upon the metabolism of 5-HT in the brain were investigated. All four drugs caused increases in the levels of 5-HT, accompanied in the early stages by decreases in the levels of 5-HIAA, suggesting that the relationship between the two substances which exists in untreated animals had been altered. No effect upon either monoamine oxidase or aromatic amino acid decarboxylase activity could be detected. The depletion of 5-HT which follows the administration of either reserpine or p-chlorophenylalanine was significantly reduced by all four drugs. These results support the theory that LSD may owe at least part of its hallucinogenic activity to an ability to alter the capacity of the tissues to bind 5-HT. Further, the demonstration that four hallucinogens of widely different structure all affect the binding of 5-HT strongly supports the implication of this action in hallucinogenesis. © 1969.