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 interaction between serotonin and excitatory amino acid agonists at rat neocortical neurons was investigated using the grease-gap recording method. Depolarization evoked by 50 microM N-methyl-D-aspartate was dose dependently facilitated by serotonin (5-HT) (1 to 100 microM) giving a bell-shaped dose-response curve with maximum enhancement at 30 microM. In contrast, quisqualate and kainate depolarizations were not enhanced. Subnanomolar concentrations of methysergide, ritanserin and spiperone, but not ICS 205-930, attenuated the 5-HT enhancement, compatible with 5-HT2, but not 5-HT1 or 5-HT3 receptor subtype involvement. Enhancement was observed with 5-HT2 receptor agonists, whereas 5-HT1 receptor subtype agonists had either no effect (1B and 1C) or reduced (1A) the N-methyl-D-aspartate depolarization. Scopolamine and prazosin reduced the N-methyl-D-aspartate depolarization and blocked facilitation induced by carbachol and phenylephrine, but not that due to 5-HT. Tetrodotoxin reduced the N-methyl-D-aspartate depolarization, but the facilitation by 5-HT persisted. Activators of protein kinase C (phorbol diacetate and 1-oleoyl-2-acetyl-sn-glycerol) did not mimic the serotonin facilitation. We conclude that serotonin enhances N-methyl-D-aspartate depolarization of rat cortical neurons through activation of 5-HT2 receptors, however the cellular mechanism underlying the facilitation remains to be established.
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PMID:Activation of 5-HT2 receptors facilitates depolarization of neocortical neurons by N-methyl-D-aspartate. 844 27

Serotonin and 5-HT3 receptors may be involved in the activation of nociceptive afferent pathways by rectal distension. In rats, intracolonic infusion of glycerol is able to trigger nociceptive inputs as evidenced by the occurrence of abdominal constrictions. This work was designed to evaluate the influence of 5-HT3 receptor antagonists on this reflex and to approach the site of action by comparing their relative efficacies according to the route of administration. Male Wistar rats (250-350 g) were surgically prepared for abdominal electromyography and a catheter was placed in the colonic lumen. Five days after surgery, electrical activity of abdominal muscles was recorded before and during (20 min) intracolonic infusion of glycerol (60% glycerol + 40% saline, rate 0.75 mL/h). Cilansetron was administered intraperitoneally, 15 min before glycerol infusion, at doses of 5 to 500 micrograms/kg. Granisetron, ondansetron and cilansetron were administered at the dose of 20 micrograms/kg by intraperitoneal (i.p.), intravenous (i.v.) or intracolonic (i.c.) routes. The number of abdominal spike bursts was used as an index of visceral nociception. Intracolonic infusion of glycerol increased significantly (P < 0.05) the number of abdominal spike bursts during the time of infusion compared with saline (30.6 +/- 6.6 vs 4.5 +/- 3.4 bursts). When administered i.p., cilansetron dose-dependently reduced the frequency of abdominal spike bursts from the dose of 20 micrograms/kg i.p. Administration i.p. of granisetron and ondansetron at this dose also significantly reduced the number of abdominal spikes (19.0 +/- 6.0 and 18.3 +/- 6.9 respectively). Cilansetron, ondansetron and granisetron were also effective by i.v. and i.c. routes, cilansetron was more active by the i.c. route. Serotonin, via 5-HT3 receptors, is involved in the mediation of abdominal contractions induced by intracolonic infusion of glycerol. 5-HT3 receptor antagonists are also active by i.c. route suggesting a local site of action.
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PMID:Intracolonic glycerol induces abdominal contractions in rats: role of 5-HT3 receptors. 981 94