In vitro effects of erythromycin, lidocaine, and metoclopramide on smooth muscle from the pyloric antrum, proximal portion of the duodenum, and middle portion of the jejunum of horses

Abstract

Regional differences in responses to erythromycin, lidocaine, and metoclopramide were evident in the gastrointestinal tract of horses. Metoclopramide increased CA in all tissues used, whereas erythromycin inhibited CA in circular smooth muscle but stimulated CA in longitudinal smooth muscle from the PA. Inhibition is caused by stimulation of inhibitory nerves and is mediated, in part, by nitric oxide and vasoactive intestinal peptide.