Effects of mosapride, a 5-hydroxytryptamine 4 receptor agonist, on electrical activity of the small intestine and cecum in horses

Abstract

Objective: To examine the effects of various doses of mosapride, a 5-hydroxytryptamine 4 receptor agonist, on motility of the small intestine and cecum in horses by use of electrical activity and to determine the dose that provides the optimal response.

Animal: 6 healthy adult Thoroughbreds.

Procedure: Electrical activity of the small intestine and cecum was recorded before and after mosapride administration by use of an electrogastrograph. Mosapride (0.5, 1, 1.5, and 2 mg/kg) was dissolved in 200 mL of water and administered orally to horses through a nasogastric tube. Three hours after drug administration, mean amplitude of electrical activity calculated for a period of 30 minutes was expressed as the percentage of the mean amplitude of electrical activity for a period of 30 minutes before drug administration.

Results: Mosapride administered orally increased the percentage of the mean amplitude of electrical activity in the small intestine and cecum in a dose-dependent manner. Mean +/- SD values differed significantly for 1, 1.5, and 2 mg/kg (127.0 +/- 12.5%, 137.7 +/- 22.2%, and 151.1 +/- 24.0%, respectively) in the small intestine and for 1.5 and 2 mg/kg (130.1 +/- 34.5% and 151.6 +/- 45.2%, respectively) in the cecum.

Conclusions and clinical relevance: Analysis of results of this study clearly documents that mosapride promotes motility in the small intestine and cecum of horses and that the optimal orally administered dosage is 1.5 to 2 mg/kg. Therefore, mosapride may be useful for treatment of horses with gastrointestinal tract dysfunction.