[Effect of cisapride on contractile activity of the gastrointestinal tract]

Cisapride strongly stimulates gastrointestinal motor activity simultaneously from stomach to jejunum in the interdigestive state. The contractile pattern in the stomach was quite similar to that of the natural interdigestive mingrating contractions (IMC) in all respects, frequency, contractile force, and coordination between the gastric body and antrum. However, the cisapride-induced IMC-like contractions in the stomach did not migrate along the small intestine, nor were accompanied by an increase of plasma motilin concentration. Furthermore, both motilin and cisapride, given during the period of phase III, did not affect the phase III activity, but carbachol abruptly stopped phase III activity if it was given during phase III activity. On the contrary, cisapride-induced contractions in the stomach are completely inhibited by atropine, pentagastrin, CCK-octapeptide, but not by secretin. These findings provide additional evidence to indicate that the cisapride-induced contractions in the stomach are identical with the natural IMC in the respect of reactons to hormonal substances. No noticeable side effects were observed. In conclusion, cisapride is a unique compound to initiate IMC-like contractions in the stomach, but the contractions were not accompanied by an increase in plasma motilin concentration and did not migrate the small intestine.