Action of the new H2-receptor antagonist oxmetidine on the duodenum of different species.

The new H2-receptor antagonist, oxmetidine was studied for its effects on the motility of the duodenum of different species. Oxmetidine did not modify basal motility of the rat and guinea pig duodenum but it reduced or abolished the contractions elicited by different spasmogenic compounds (acetylcholine, BaCl2, KCl, eledoisin). In the rabbit duodenum, oxmetidine reduced in a dose-dependent fashion the basal motility. The effect of this compound appears to be indirect on the smooth muscle and not mediated through specific receptors. Experiments performed in Ca++-free and K+-depolarizing solution suggest that oxmetidine acts through interference with the transport and/or utilization of intracellular Ca++ions.