Abstract
1. 5-Hydroxytryptamine (5-HT) is able to potentiate the contractions induced by electrical field stimulation of pieces of human isolated urinary bladder. On the basis of available selective 5-HT agonists and antagonists, we have further investigated the receptors involved and their site of action. 2. 5-HT produced a concentration-dependent increase of the contractile response to electrical field stimulation from 0.1 nM to 1 microM. At higher concentrations (up to 100 microM) the effect decreased. These activities were mimicked by a variety of 5-HT agonists, for which the following rank order of potency was found: 5-HT greater than alpha-methyl 5-HT greater than 5-methoxytryptamine greater than 5-carboxamidotryptamine greater than 2-methyl 5-HT much greater than GR 43175. In addition the gastro-prokinetics agents metoclopramide, cisapride and the 5-HT3 antagonist ICS 205-930 behaved as 5-HT agonists, their EC50 values being 2.3, 0.3, and 0.5 (microM) respectively. 3. The 5-HT potentiating effect was resistant to antagonism by ondansetron (1 microM) and cyanopindolol (1 microM), selective 5-HT3 and 5-HT1A/1B antagonists respectively. The 5-HT2 antagonists ketanserin (1 microM), spiperone (1 microM) and methysergide (1 microM) also showed a weak inhibitory activity. Methiothepin (0.1-1 microM) antagonized only the inhibitory effect of 5-HT. Metoclopramide (0.1-1 microM), cisapride (0.01-0.1 microM) and ICS 205-930 (0.3-3 microM) all produced a rightward displacement of the 5-HT response curve with concomitant reduction of the maximum response.(ABSTRACT TRUNCATED AT 250 WORDS)
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- ARUNLAKSHANA O., SCHILD H. O. Some quantitative uses of drug antagonists. Br J Pharmacol Chemother. 1959 Mar;14(1):48–58. doi: 10.1111/j.1476-5381.1959.tb00928.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bradley P. B., Engel G., Feniuk W., Fozard J. R., Humphrey P. P., Middlemiss D. N., Mylecharane E. J., Richardson B. P., Saxena P. R. Proposals for the classification and nomenclature of functional receptors for 5-hydroxytryptamine. Neuropharmacology. 1986 Jun;25(6):563–576. doi: 10.1016/0028-3908(86)90207-8. [DOI] [PubMed] [Google Scholar]
- Craig D. A., Clarke D. E. Pharmacological characterization of a neuronal receptor for 5-hydroxytryptamine in guinea pig ileum with properties similar to the 5-hydroxytryptamine receptor. J Pharmacol Exp Ther. 1990 Mar;252(3):1378–1386. [PubMed] [Google Scholar]
- DeLean A., Munson P. J., Rodbard D. Simultaneous analysis of families of sigmoidal curves: application to bioassay, radioligand assay, and physiological dose-response curves. Am J Physiol. 1978 Aug;235(2):E97–102. doi: 10.1152/ajpendo.1978.235.2.E97. [DOI] [PubMed] [Google Scholar]
- Dumuis A., Bouhelal R., Sebben M., Cory R., Bockaert J. A nonclassical 5-hydroxytryptamine receptor positively coupled with adenylate cyclase in the central nervous system. Mol Pharmacol. 1988 Dec;34(6):880–887. [PubMed] [Google Scholar]
- Dumuis A., Sebben M., Bockaert J. The gastrointestinal prokinetic benzamide derivatives are agonists at the non-classical 5-HT receptor (5-HT4) positively coupled to adenylate cyclase in neurons. Naunyn Schmiedebergs Arch Pharmacol. 1989 Oct;340(4):403–410. doi: 10.1007/BF00167041. [DOI] [PubMed] [Google Scholar]
- Fozard J. R. MDL 72222: a potent and highly selective antagonist at neuronal 5-hydroxytryptamine receptors. Naunyn Schmiedebergs Arch Pharmacol. 1984 May;326(1):36–44. doi: 10.1007/BF00518776. [DOI] [PubMed] [Google Scholar]
- GADDUM J. H., PICARELLI Z. P. Two kinds of tryptamine receptor. Br J Pharmacol Chemother. 1957 Sep;12(3):323–328. doi: 10.1111/j.1476-5381.1957.tb00142.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hindmarsh J. R., Idowu O. A., Yeates W. K., Zar M. A. Pharmacology of electrically evoked contractions of human bladder [proceedings]. Br J Pharmacol. 1977 Sep;61(1):115P–115P. [PMC free article] [PubMed] [Google Scholar]
- Holt S. E., Cooper M., Wyllie J. H. On the nature of the receptor mediating the action of 5-hydroxytryptamine in potentiating responses of the mouse urinary bladder strip to electrical stimulation. Naunyn Schmiedebergs Arch Pharmacol. 1986 Dec;334(4):333–340. doi: 10.1007/BF00569366. [DOI] [PubMed] [Google Scholar]
- Humphrey P. P., Feniuk W., Perren M. J., Connor H. E., Oxford A. W., Coates L. H., Butina D. GR43175, a selective agonist for the 5-HT1-like receptor in dog isolated saphenous vein. Br J Pharmacol. 1988 Aug;94(4):1123–1132. doi: 10.1111/j.1476-5381.1988.tb11630.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Humphrey P. P. Peripheral 5-hydroxytryptamine receptors and their classification. Neuropharmacology. 1984 Dec;23(12B):1503–1510. doi: 10.1016/0028-3908(84)90094-7. [DOI] [PubMed] [Google Scholar]
- Leysen J. E., Awouters F., Kennis L., Laduron P. M., Vandenberk J., Janssen P. A. Receptor binding profile of R 41 468, a novel antagonist at 5-HT2 receptors. Life Sci. 1981 Mar 2;28(9):1015–1022. doi: 10.1016/0024-3205(81)90747-5. [DOI] [PubMed] [Google Scholar]
- Reeves J. J., Bunce K. T., Humphrey P. P., Gunning S. J. Further characterisation of the 5-HT receptor mediating smooth muscle relaxation in rat oesophagus. Br J Pharmacol. 1989 Dec;98 (Suppl):800P–800P. [PubMed] [Google Scholar]
- Richardson B. P., Engel G., Donatsch P., Stadler P. A. Identification of serotonin M-receptor subtypes and their specific blockade by a new class of drugs. Nature. 1985 Jul 11;316(6024):126–131. doi: 10.1038/316126a0. [DOI] [PubMed] [Google Scholar]
- Sanger G. J. Activation of a myenteric 5-hydroxytryptamine-like receptor by metoclopramide. J Pharm Pharmacol. 1987 Jun;39(6):449–453. doi: 10.1111/j.2042-7158.1987.tb03418.x. [DOI] [PubMed] [Google Scholar]
- VAN ROSSUM J. M. Cumulative dose-response curves. II. Technique for the making of dose-response curves in isolated organs and the evaluation of drug parameters. Arch Int Pharmacodyn Ther. 1963;143:299–330. [PubMed] [Google Scholar]
- Wardle K. A., Sanger G. J. Atypical 5-HT receptors in guinea-pig isolated ileum. Br J Pharmacol. 1989 Dec;98 (Suppl):801P–801P. [PubMed] [Google Scholar]
