Erythromycin mimics exogenous motilin in gastrointestinal contractile activity in the dog

Abstract

The gastrointestinal motor stimulating activity of erythromycin (EM) was studied in conscious dogs. It was found that a 20-min i.v. infusion of EM lactobionate at a dose of 50-100 .mu.g (potency) .cntdot. kg-1 .cntdot. h-1 induced a group of strong contractions in the stomach and the duodenum, and the contractions migrated along the small intestine to the terminal ileum. The EM-induced contractions were quite similar to the naturally occurring interdigestive migrating contractions (IMC) in the gastrointestinal tract in frequency, contractile force and duration of the contractions, migrating velocity and accompanying peaks of plasma motilin concentration. The EM-induced contractions in the stomach were inhibited by feeding and i.v. infusion of pentagastrin (1.5 .mu.g .cntdot. kg-1 .cntdot. h-1) but were not affected by secretin; these findings were identical to those found with the naturally occurring and motilin-induced contractions. Like motilin, EM stimulated motor activity only during the interdigestive state. EM evidently induces IMC associated with the release of endogenous motilin in the dog.