Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P46098 (5-HT3 receptor)
 2,290 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The involvement of 5-hydroxytryptamine (5-HT) in gastric function and mucosal damage has been defined. 5-HT also potentiates lesion formation in animals. The current study investigated further whether these actions are mediated through 5-HT3 receptors in rats. Ondansetron, a 5-HT3 receptor antagonist, was given subcutaneously, 2 or 4 mg/kg, 30 min before the gastric parameters were measured. The higher dose of ondansetron, 4 mg/kg, significantly increased gastric mucosal blood flow (GMBF) and also basal acid and Na+ secretion. However, it did not affect pepsin output. 5-HT time dependently reduced GMBF and pepsin secretion, but not that of acid and Na+. These actions were not altered by ondansetron pretreatment. The drug, however, dose dependently reduced ethanol-induced gastric mucosal lesions in the 5-HT-treated animals. These findings indicate that 5-HT3 receptors regulate not only basal GMBF, but also acid and Na+ secretion in stomachs. However, the depressive action of 5-HT on GMBF and pepsin secretion is most likely not mediated through 5-HT3 receptors. Ondansetron also modulates the toxicities of ethanol in the stomach and this action is likely to be mediated through the preservation of GMBF.
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PMID:Modulatory role of 5-HT3 receptors in gastric function and ethanol-induced mucosal damage in rat stomachs. 797 27

Serotonin (5-hydroxytryptamin; 5-HT) content has been measured using high-performance liquid chromatography with electrochemical detection (HPLC-ECD). The distributions of 5-HT-containing cells and 5-HT3 receptors have been determined with specific antibodies against 5-HT and 5-HT3 receptors, respectively. The effect of serotonin on acid secretion has been studied using an isolated rat stomach model. It has been shown that 5-HT concentrations in the fundus, mucosal layers of the corpus, remaining layer of the corpus and antrum are approximately 152, 498, 1494 and 972 nmol/mg protein, respectively. The distribution of 5-HT-containing cells is concentrated in the enteric plexus and enterochromaffin (EC) cells in the deep mucosal layer. Immunoreactivity to 5-HT3 receptors is localized in numerous neurons of the myenteric and submucosal plexus and concentrated in the neuronal plasma membrane, submucosa, endocrine cells and lamina propria. In the present study, the effect of 5-HT on gastric acid secretion was investigated on an everted preparation of isolated rat stomach. 5-HT at 1-100 microM reduced acid secretion stimulated by oxotremorine while 10 microM 5-HT did not modify the basal secretion of gastric acid. We further showed that 10 microM 5-HT reduced acid secretion and pepsin output stimulated by oxotremorine, histamine and pentagastrin; among the 5-HT receptors agonists tested, 2-methyl-5-HT (1-10 microM), a 5-HT3 receptor agonist, inhibited oxotremorine-, histamine- and pentagastrin-stimulated acid secretions, and this inhibitory effect was blocked by 1 microM MDL 72222, a specific 5-HT3 receptor antagonist. These results suggest that 5-HT is released from serotoninergic neurons, their processes and EC cells. The effect of 5-HT mediated by 5-HT3 receptors involves distinct neuronal and non-neuronal pathways which modulate gastric acid secretion.
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PMID:Effects of serotonin on acid secretion in isolated rat stomach: the role of 5-HT3 receptors. 2035 30