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Updated: Aug 5, 2026

Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents.
Published on: September 18, 2014
Functional evidence for a 5-HT2B receptor mediating contraction of longitudinal muscle in human small intestine
1Department of Pharmacology, Queen Mary and Westfield College, London.
Abstract:
Application of 5-hydroxytryptamine induces contraction of longitudinal muscle strips from human terminal ileum. The response was resistant to antagonism by ketanserin, ondansetron or DAU6285, but was non-surmountably antagonized by methysergide. The selective 5-HT2B/2C receptor antagonist, SB 200646A evoked a concentration-dependent, parallel and dextral displacement of the concentration-response curve to 5-HT, yielding a pA2 estimate of 7.17. Application of yohimbine, a 5-HT1 and 5-HT2B receptor antagonist, also induced a rightward shift of the response curve to 5-HT, yielding a pA2 estimate of 8.10. In conclusion, it appears that a 5-HT2B receptor mediates the contractile response of the longitudinal muscle of human small intestine to 5-HT.
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