KW-5092

The present study was designed to determine the influence of KW-5092 ((1-[2-[[[5-(piperidinomethyl)-2-furanyl]methyl]amino]ethyl]-2- imidazolidinylidene) propanedinitrile fumarate), a novel gastroprokinetic agent on intraluminal serotonin (5-hydroxytryptamine, 5-HT) release which reflects the release of 5-HT from enterochromaffin cells, using the luminally perfused isolated guinea-pig proximal colon in vitro. 5-HT was determined by high-performance liquid chromatography with electrochemical detection. KW-5092 (1-10 microM) concentration-dependently caused an increase in the luminal 5-HT outflow. In the presence of atropine (0.2 microM) or tetrodotoxin (0.3 microM), the stimulatory action of KW-5092 (10 microM) was inhibited by 94% and 74%, respectively. These results suggest that KW-5092 stimulates intraluminal 5-HT release from luminally perfused proximal colon of the guinea-pig via the stimulation of cholinergic neurons. Because 5-HT is recognized as an important messenger substance in the control of intestinal motility, this stimulatory effect could be considered as an indirect action of KW-5092 that may contribute to its prokinetic effects.

KW-5092 (2-[1-[2-[[5-(piperidinomethyl)-2-furanyl]methylamino]ethyl]imidazonylidin-2-ylidenene]malononitrile fumarate) is a novel gastroprokinetic agent with both acetylcholine release facilitatory and acetylcholinesterase inhibitory activity. We have investigated the effects of KW-5092 on antroduodenal coordination and gastric emptying in guinea-pigs.In the guinea-pig isolated gastroduodenal preparation, KW-5092 at 3 times 10−7 to 3 times 10−6 M significantly increased antroduodenal coordination. The effect of KW-5092 was almost completely inhibited by atropine or tetrodotoxin. Cisapride, a gastroprokinetic agent with acetylcholine release facilitatory activity, also increased coordination whereas neither acetylcholine nor the acetylcholinesterase inhibitor neostigmine affected it. In-vivo, KW-5092 and cisapride enhanced gastric emptying whereas neostigmine delayed it.These results suggest that acetylcholine release facilitation, but not acetylcholinesterase inhibition, is involved in the enhancement by KW-5092 of antroduodenal coordination and gastric emptying.