Contractile responses to tryptamine analogues in isolated smooth muscle.
Tryptamine and its benzo[b]thiophene and 1-methylindole analogues had a lower affinity for receptors in rat stomach fundus strips than did serotonin; the interaction between serotonin and methysergide in this system was competitive, while the interactions between tryptamine and its analogues and methysergide were noncompetitive. In contrast, the affinity of tryptamine and 1-methyl-tryptamine for receptors in rat aorta strips was greater than the affinity for serotonin; all three compounds showed noncompetitive interactions with methysergide. The results support the hypothesis of differing serotonin receptors in the two tissues.
D000818:Animals; D001011:Aorta / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D011706:Pyloric Antrum / Q000187:drug effects; D051381:Rats; D014363:Tryptamines / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D014363:Tryptamines; D009638:Norepinephrine; D008784:Methysergide