Cerebral and peripheral demethylation of psychotomimetics measured by expired 14CO2

Int J Rad Appl Instrum B. 1989;16(1):91-9. doi: 10.1016/0883-2897(89)90219-5.

Abstract

Demethylation of psychotomimetic compounds was measured by labeling each methyl and methoxy substitutent separately with 14C and injecting it into rats, intravenously and intracerebrally. Expired [14C]CO2 was measured continuously and the resultant multi-exponential curves yielded rates and integral demethylation. 5-Methoxy-N,N-dimethyltryptamine was not demethylated, eliminating one proposed metabolic pathway. 2,4,5-Trimethoxyphenalkylamines were demethylated less in the brain than peripherally, markedly so at the p-methoxy position, suggesting a possible biochemical site for endogenous induction of psychosis.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amphetamines / administration & dosage
  • Amphetamines / pharmacokinetics*
  • Animals
  • Biotransformation
  • Brain / metabolism*
  • Carbon Dioxide / analysis*
  • Carbon Radioisotopes / analysis
  • Hallucinogens / administration & dosage
  • Hallucinogens / pharmacokinetics*
  • Humans
  • Injections
  • Injections, Intravenous
  • Methoxydimethyltryptamines / pharmacokinetics*
  • Methylation
  • Molecular Structure
  • Phenethylamines / administration & dosage
  • Phenethylamines / pharmacokinetics*
  • Rats
  • Rats, Inbred Strains
  • Receptors, Serotonin / metabolism
  • Schizophrenia / metabolism
  • Structure-Activity Relationship
  • Tryptamines / pharmacokinetics*

Substances

  • Amphetamines
  • Carbon Radioisotopes
  • Hallucinogens
  • Methoxydimethyltryptamines
  • Phenethylamines
  • Receptors, Serotonin
  • Tryptamines
  • 2,4,5-trimethoxyphenylisopropylamine
  • Carbon Dioxide
  • 2,4,5-trimethoxyphenethylamine