Expression and function of 5-hydroxytryptamine 4 receptors in smooth muscle preparations from the duodenum, ileum, and pelvic flexure of horses without gastrointestinal tract disease

Prause, A.S.; Guionaud, Christophe; Stoffel, Michael Hubert; Portier, C.J.; Mevissen, Meike (2010). Expression and function of 5-hydroxytryptamine 4 receptors in smooth muscle preparations from the duodenum, ileum, and pelvic flexure of horses without gastrointestinal tract disease. American journal of veterinary research, 71(12), pp. 1432-42. Chicago, Ill.: American Veterinary Medical Association 10.2460/ajvr.71.12.1432

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OBJECTIVE: To evaluate the expression of the 5-hydroxytryptamine 4 (5-HT4) receptor subtype and investigate the modulating function of those receptors on contractility in intestinal tissues obtained from horses without gastrointestinal tract disease. SAMPLE POPULATION: Smooth muscle preparations from the duodenum, ileum, and pelvic flexure collected immediately after slaughter of 24 horses with no history or signs of gastrointestinal tract disease. PROCEDURES: In isometric organ baths, the contractile activities of smooth muscle preparations in response to 5-hydroxytryptamine and electric field stimulation were assessed; the effect of tegaserod alone or in combination with 5-hydroxytryptamine on contractility of intestinal specimens was also investigated. Presence and distribution of 5-HT4 receptors in intestinal tissues and localization on interstitial cells of Cajal were examined by use of an immunofluorescence technique. RESULTS: Widespread 5-HT4 receptor immunoreactivity was observed in all intestinal smooth muscle layers; 5-HT4 receptors were absent from the myenteric plexus and interstitial cells of Cajal. In electrical field-stimulated tissue preparations of duodenum and pelvic flexure, tegaserod increased the amplitude of smooth muscle contractions in a concentration-dependent manner. Preincubation with tegaserod significantly decreased the basal tone of the 5-HT-evoked contractility in small intestine specimens, compared with the effect of 5-HT alone, thereby confirming that tegaserod was acting as a partial agonist. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, 5-HT4 receptors on smooth muscle cells appear to be involved in the contractile response of the intestinal tract to 5-hydroxytryptamine. Results suggest that tegaserod may be useful for treatment of reduced gastrointestinal tract motility in horses.

Item Type:	Journal Article (Original Article)
Division/Institute:	05 Veterinary Medicine > Department of Clinical Research and Veterinary Public Health (DCR-VPH) > Veterinary Pharmacology and Toxicology 05 Veterinary Medicine > Department of Clinical Research and Veterinary Public Health (DCR-VPH) > Veterinary Anatomy
UniBE Contributor:	Guionaud, Christophe, Stoffel, Michael Hubert, Mevissen, Meike
Subjects:	600 Technology > 630 Agriculture 500 Science > 570 Life sciences; biology
ISSN:	0002-9645
Publisher:	American Veterinary Medical Association
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:17
Last Modified:	05 Dec 2022 14:04
Publisher DOI:	10.2460/ajvr.71.12.1432
URI:	https://boris.unibe.ch/id/eprint/4983 (FactScience: 209648)