Human colonic mucosa possesses a mixed population of 5-HT receptors.
The aim of this study was to characterise the 5-HT receptor(s) mediating secretory responses of isolated human colonic mucosa to 5-HT. Sheets of muscle-stripped mucosa from proximal (ascending) and distal (sigmoid) human colon were set up in Ussing chambers for measurement of short-circuit current (Isc). Serosal application of 5-HT led to non-neural, concentration-dependent increases in Isc. Desensitisation to 5-HT was observed with ascending and sigmoid colonic mucosa. Using selective 5-HT antagonists we have shown that 5-HT induces secretion in sigmoid colon via a 5-HT2A receptor. In ascending colon a combination of 5-HT2A and 5-HT4 receptors appears to be involved.
Borman
R A
RA
Department of Pharmacology, Queen Mary and Westfield College, London, UK.
Burleigh
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DE
D005576:Colforsin / Q000494:pharmacology; D003106:Colon / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000145:classification / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology
D011985:Receptors, Serotonin; D005576:Colforsin; D012701:Serotonin