Preliminary investigations of the metabolism and pharmacological activity of beta-hydroxytryptamines in mammals

• Published in: Journal of pharmacy and pharmacology Vol. 28; no. 5; p. 424
• Main Authors: Plavsić, V, Iskrić, S, Kveder, S, Tućan-Foretić, M, Wolf, D, Gjuris, V, Supek, Z
• Format: Journal Article
• Language: English
• Published: England 01.05.1976
• Subjects: Animals; Blood Pressure - drug effects; Deamination; Electrocardiography; Female; Guinea Pigs; Ileum - drug effects; In Vitro Techniques; Kinetics; Liver - metabolism; Muscle, Smooth - drug effects; Oxygen Consumption - drug effects; Rats; Respiration - drug effects; Serotonin - analogs & derivatives; Serotonin - chemical synthesis; Serotonin - metabolism; Serotonin - pharmacology
• ISSN: 0022-3573
• DOI: 10.1111/j.2042-7158.1976.tb04647.x

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.