Short-circuit current responses to 5-hydroxytryptamine in human ileal mucosa are mediated by a 5-HT4 receptor.
5-Hydroxytryptamine (5-HT) increases short-circuit current when added to the serosal side of human isolated ileal mucosa; mucosally applied 5-HT was ineffective. Tetrodotoxin reduced both basal short-circuit current and increases in short-circuit current due to electrical field stimulation of mucosal nerves. However, neither tetrodotoxin, ondansetron nor methysergide plus ketanserin affected 5-HT induced increases in short-circuit current. Application of SDZ 205-557 (2-diethylaminoethyl-(2-methoxy-4-amino-5-chloro) benzoate) to the tissue caused a significant increase in the concentration ratio between two successive 5-HT response curves. It is concluded that the effect of 5-HT on short-circuit current of human ileal mucosa appears to be due to stimulation of a 5-HT4 receptor.
Burleigh
D E
DE
Department of Pharmacology, Queen Mary and Westfield College, London, UK.
Borman
R A
RA
D005576:Colforsin / Q000494:pharmacology; D004558:Electric Stimulation; D006801:Humans; D007082:Ileum / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists; D013779:Tetrodotoxin / Q000494:pharmacology
D007473:Ion Channels; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D005576:Colforsin; D012701:Serotonin; D013779:Tetrodotoxin