The involvement of opiate receptors in the effects of trimebutine on intestinal motility in the conscious dog.

The effects of intravenous (i.v.) vs intracerebroventricular (i.c.v.) administration of trimebutine on the motility of the small intestine and colon of fasted dogs were assessed using chronic electromyography. Trimebutine, injected intravenously, stimulated small intestinal motility, by inducing a propagated phase of regular spike activity, and inhibited colonic motility for some 4 h. These effects were not reproduced by i.c.v. administration which disrupted the cyclic motor profile of the small intestine for about 2.5 h and did not modify colonic motility. The stimulation of the small intestine motility induced by i.v. administration of the drug was blocked by previous i.v. but not by i.c.v. administration of naloxone. It was concluded that in the dog, the effects of trimebutine on the small intestine but not on the colon, involve peripheral opiate receptors.