Preliminary investigations of the metabolism and pharmacological activity of beta-hydroxytryptamines in mammals.
beta-Hydroxytryptamine and beta-hydroxy-5-hydroxytryptamine were incubated with rat liver slices and oxidative deamination was established as the main route of metabolism: in both instances the corresponding indole-3-glycollic acids and indole-3-ethane diols were the major metabolites. However, the rates of deamination of beta-hydroxylated tryptamines, as measured manometrically, were found to be much slower than those of tryptamines nonhydroxylated in the side chain. The pharmacological activities of beta-hydroxylated tryptamines were tested in guinea-pigs on resistance of respiratory pathways, spontaneous respiration, electrocardiogram, blood pressure and isolated ileum, using tryptamine and 5-HT as reference substances. The effects of tryptamines hydroxylated in the side chain were in general similar to those of corresponding tryptamines but of much lower intensities; only in increasing the blood pressure was beta-hydroxytryptamine as active as tryptamine. The different reactions of these two groups of substances in the presence of some antagonists indicate that the receptors are probably not the same.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003641:Deamination; D004562:Electrocardiography; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D009130:Muscle, Smooth / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D012119:Respiration / Q000187:drug effects; D012701:Serotonin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology
D012701:Serotonin