Prokinetic actions of luminally acting 5-HT4 receptor agonists.

Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society 2021 Apr

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5-HT4 receptor (5-HT4 R) agonists exert prokinetic actions in the GI tract, but non-selective actions and potential for stimulation of non-target 5-HT4 Rs have limited their use. Since 5-HT4 Rs are expressed in the colonic epithelium and their stimulation accelerates colonic propulsion in vitro, we tested whether luminally acting 5-HT4 R agonists promote intestinal motility. Non-absorbed 5-HT4 R agonists, based on prucalopride and naronapride, were assessed for potency at the 5-HT4 R in vitro, and for tissue and serum distribution in vivo in mice. In vivo assessment of prokinetic potential included whole gut transit, colonic motility, fecal output, and fecal water content. Colonic motility was also studied ex vivo in mice treated in vivo. Immunofluorescence was used to evaluate receptor distribution in human intestinal mucosa. Pharmacological screening demonstrated selectivity and potency of test agonists for 5-HT4 R. Bioavailability studies showed negligible serum detection. Gavage of agonists caused faster whole gut transit and colonic motility, increased fecal output, and elevated fecal water content. Prokinetic actions were blocked by a 5-HT4 R antagonist and were not detected in 5-HT4 R knockout mice. Agonist administration promoted motility in models of constipation. Evaluation of motility patterns ex vivo revealed enhanced contractility in the middle and distal colon. Immunoreactivity for 5-HT4 R is present in the epithelial layer of the human small and large intestines. These findings demonstrated that stimulation of epithelial 5-HT4 Rs can potentiate propulsive motility and support the concept that mucosal 5-HT4 Rs could represent a safe and effective therapeutic target for the treatment of constipation. © 2020 John Wiley & Sons Ltd.

Citation

John R Konen, Melody M Haag, Daria Guseva, Molly Hurd, Alisha A Linton, Brigitte Lavoie, Colleen B Kerrigan, Emily Joyce, Stephan C Bischoff, Steve Swann, Luana Griffin, Jun Matsukawa, Matthew D Falk, Tony S Gibson, Grant W Hennig, Jill Wykosky, Gary M Mawe. Prokinetic actions of luminally acting 5-HT4 receptor agonists. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society. 2021 Apr;33(4):e14026