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 effect of heat-stable E. coli enterotoxin on intestinal fluid secretion is commonly considered to be mediated by stimulation of mucosal cyclic guanosine monophosphate (cGMP). It was demonstrated recently that 5-hydroxytryptamine (5-HT) acts as an important mediator in cholera toxin-induced fluid secretion. To elucidate the possible involvement of 5-HT in the secretory response to heat-stable E. coli enterotoxin, in vivo experiments were performed in the rat jejunum. The inhibitory effects of the 5-HT2 receptor antagonist ketanserin, the 5-HT3 receptor antagonist tropisetron and indomethacin were studied in heat-stable E. coli enterotoxin-induced fluid secretion. Tropisetron and ketanserin (100 micrograms/kg each) alone only partially reduced the secretory effect of the toxin. However, in combination, the two blockers (100 plus 100 micrograms/kg) significantly reduced and at 200 plus 200 micrograms/kg totally abolished heat-stable E. coli enterotoxin-induced secretion without influencing the enterotoxin-induced increase in cGMP. Pretreatment with indomethacin (10 mg/kg) reduced the secretory response to the enterotoxin by about 50%. These results support the concept that 5-HT is an important mediator in intestinal fluid secretion induced by heat-stable E. coli enterotoxin. The enterotoxin may use 5-HT to stimulate prostaglandin formation via 5-HT2 receptors and to activate neuronal structures via 5-HT3 receptors.
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PMID:5-HT receptor antagonists and heat-stable Escherichia coli enterotoxin-induced effects in the rat. 133 Jun 11

1. The present study investigated the presence of 5-HT3 receptor using 2-methylserotonin (2-Me-5-HT) in the smooth muscle of Mytilus ABRM. 2. 2-Me-5-HT relaxed the acetylcholine-induced contraction in a dose-dependent manner ranging from 10(-6) to 3 x 10(-4) M (pD2 = 5.55 +/- 0.32). 3. 2-Me-5-HT-induced relaxation was antagonized by 3 x 10(-5) M ketanserin in a competitive manner (pA2 = 5.14 +/- 0.1), but not by cypropheptadine, mianserin, MDL 72222 or ICS 205-930 at a concentration of 3 x 10(-5) M. 4. 2-Me-5-HT (3 x 10(-4) M) did not alter the content of cyclic AMP and cyclic GMP in the ABRM. 5. These findings suggested that the 2-Me-5-HT-induced relaxation was mediated through 5-HT2-like receptors and was not linked to cyclic AMP or GMP systems, and, further, that 5-HT3 receptor subtype was not present in the ABRM.
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PMID:Possible site of action of 2-methylserotonin in inducing relaxation of acetylcholine-induced contraction in the molluscan (Mytilus edulis) smooth muscle. 135 10