Review article: 5-hydroxytryptamine agonists and antagonists in the modulation of gastrointestinal motility and sensation: clinical implications.
Serotonin (5-hydroxytryptamine; 5-HT) is found in the enteric nervous system where it has been implicated in controlling gastrointestinal motor function. A number of receptor or recognition sites have been identified in the gut, but recently most attention has focused on the 5-HT3 and 5-HT4 receptors. The functional role of the 5-HT3 receptor remains incompletely understood, but it is probably involved in the modulation of colonic motility and visceral pain in the gut. A number of selective 5-HT3 antagonists have been developed including ondansetron, granisetron, tropisetron renzapride and zacopride. While the substituted benzamide prokinetics (for example, metoclopramide, cisapride) also block 5-HT3 receptors in high concentrations, their prokinetic action is believed to be on the basis of their agonist effects on the putative 5-HT4 receptor. Some 5-HT3 antagonists have 5-HT4 agonist activity (for example, renzapride, zacopride) and others do not (for example, ondansetron, granisetron), while tropisetron in high concentrations is a 5-HT4 antagonist. Based on the pharmacological data, it has been suggested that specific 5-HT antagonists and agonists may prove to be beneficial in a number of gastrointestinal disorders including the irritable bowel syndrome, functional dyspepsia, non-cardiac chest pain, gastrooesophageal reflux and refractory nausea. In this review, the rationale for the use of these compounds is discussed, and the available experimental evidence is summarized.
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CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL GENE-Y CHEMICAL GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL
zacopride benzamide metoclopramide cisapride renzapride zacopride ondansetron granisetron 5-hydroxytryptamine 5-HT4 Serotonin 5-HT3 5-HT4 5-HT3 5-HT3 5-HT3 5-HT4 5-HT3 5-HT4 tropisetron 5-hydroxytryptamine 5-HT 5-HT ondansetron granisetron tropisetron renzapride