Effects of three tryptamines: alpha-methyltryptamine, 5-methoxy-alpha-methyltryptamine, and 5-methoxy-N,N-diisopropyltryptamine on acute toxicity, locomotor activity, and hallucinogenic behavior in mice.

Alpha-methyltryptamine (AMT), 5-methoxy-alpha-methyltryptamine (5-MeO-AMT), and 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DiPT) are synthetic tryptamines with hallucinogenic-like properties that are widely abused worldwide. There, however, has been a paucity of research and a lack of available data on their pharmacological properties. The objective of this study was to investigate the safety of AMT and 5-MeO-DiPT and to compare the effects of AMT, 5-MeO-AMT, and 5-MeO-DiPT under identical conditions in terms of locomotor performance and hallucinogenic-like behavior, and the role of 5-hydroxytryptamine-2A receptor antagonists (M100907) on hallucinogenic-like behavior. The results showed that both AMT and 5-MeO-DiPT exhibited some acute toxic effects. AMT, 5-MeO-AMT, and 5-MeO-DiPT inhibited locomotor activity and induced head-twitch response (HTR) in mice. Pretreatment with M100907 (0.01 mg/kg) blocked AMT, 5-MeO-AMT, and 5-MeO-DiPT induced HTR in mice. The findings of this study demonstrated that the three tryptamines are toxic, inhibit locomotor activity, and have hallucinogenic effects. These results provide experimental data that can provide fundamental support for future control strategies and in-depth mechanistic studies of these substances.