Skip to main content
PMC home page
British Journal of Pharmacology logoLink to British Journal of Pharmacology
. 1995 Jan;114(1):73–76. doi: 10.1111/j.1476-5381.1995.tb14907.x

An enhancing effect of 5-hydroxytryptamine on electrically evoked atropine-resistant contraction of guinea-pig proximal colon.

S Kojima 1, Y Shimo 1
PMCID: PMC1510169  PMID: 7712032

Abstract

1. In the presence of atropine (0.2 microM) and indomethacin (2 microM), the effects of 5-hydroxytryptamine (5-HT) have been studied on electrically-evoked, neurogenic contractions of the guinea-pig proximal colon in vitro. 2. 5-HT, at higher concentrations than 1 nM, caused an increase in electrically (1 Hz, 0.3 ms, 160 mA)-evoked, atropine-resistant contractions in a concentration-dependent manner and at 30 nM produced a maximal effect (pEC50 value of 8.20 +/- 0.11, n = 6). The enhancing effects of 5-HT on the electrically evoked contractions were mimicked by alpha-methyl-5-HT (pEC50 value of 6.59 +/- 0.05, n = 6). 3. Both hexamethonium (100 microM) and spantide (10 microM), selective antagonists for nicotinic and tachykinin receptors respectively, significantly reduced the enhancement of the electrically evoked contractions by 5-HT (30 nM). 4. DAU 6285 (3 microM), a 5-HT4 receptor antagonist, abolished the enhancing action of 5-HT (30 nM), but metitepine (0.03 microM), a 5-HT1/5-HT2 receptor antagonist, ketanserin (0.01 microM), a 5-HT2 receptor antagonist, and ondansetron (1 microM), a 5-HT3 receptor antagonist, had no effect on the enhancement. The enhancing effects of alpha-methyl-5-HT (1 microM) were also abolished by DAU 6285 (3 microM). 5. Both 5-HT (30 nM) and alpha-methyl-5-HT (1 microM) had no effect on contractions to exogenous substance P (0.15-0.3 nM).(ABSTRACT TRUNCATED AT 250 WORDS)

Full text

PDF
73

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Baxter G. S., Craig D. A., Clarke D. E. 5-Hydroxytryptamine4 receptors mediate relaxation of the rat oesophageal tunica muscularis mucosae. Naunyn Schmiedebergs Arch Pharmacol. 1991 May;343(5):439–446. doi: 10.1007/BF00169544. [DOI] [PubMed] [Google Scholar]
  2. 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]
  3. Clarke D. E., Craig D. A., Fozard J. R. The 5-HT4 receptor: naughty, but nice. Trends Pharmacol Sci. 1989 Oct;10(10):385–386. doi: 10.1016/0165-6147(89)90177-6. [DOI] [PubMed] [Google Scholar]
  4. Costa M., Furness J. B. The sites of action of 5-hydroxytryptamine in nerve-muscle preparations from the guinea-pig small intestine and colon. Br J Pharmacol. 1979 Feb;65(2):237–248. doi: 10.1111/j.1476-5381.1979.tb07824.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dumuis A., Gozlan H., Sebben M., Ansanay H., Rizzi C. A., Turconi M., Monferini E., Giraldo E., Schiantarelli P., Ladinsky H. Characterization of a novel 5-HT4 receptor antagonist of the azabicycloalkyl benzimidazolone class: DAU 6285. Naunyn Schmiedebergs Arch Pharmacol. 1992 Mar;345(3):264–269. doi: 10.1007/BF00168685. [DOI] [PubMed] [Google Scholar]
  6. Elswood C. J., Bunce K. T., Humphrey P. P. Identification of putative 5-HT4 receptors in guinea-pig ascending colon. Eur J Pharmacol. 1991 Apr 17;196(2):149–155. doi: 10.1016/0014-2999(91)90421-l. [DOI] [PubMed] [Google Scholar]
  7. Galligan J. J. Differential inhibition of cholinergic and noncholinergic neurogenic contractions by 5-hydroxytryptamine1A receptor agonists in guinea pig ileum. J Pharmacol Exp Ther. 1992 Jan;260(1):306–312. [PubMed] [Google Scholar]
  8. Giuliani S., Lecci A., Giachetti A., Maggi C. A. Tachykinins and reflexly evoked atropine-resistant motility in the guinea pig colon in vivo. J Pharmacol Exp Ther. 1993 Jun;265(3):1224–1231. [PubMed] [Google Scholar]
  9. Kojima S. Characterization of 5-hydroxytryptamine-induced relaxations of guinea-pig proximal colon. Arch Int Pharmacodyn Ther. 1991 Sep-Oct;313:23–32. [PubMed] [Google Scholar]
  10. Medhurst A. D., Kaumann A. J. Characterization of the 5-HT4 receptor mediating tachycardia in piglet isolated right atrium. Br J Pharmacol. 1993 Nov;110(3):1023–1030. doi: 10.1111/j.1476-5381.1993.tb13916.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Mizutani M., Neya T., Nakayama S. Ascending contraction mediated by 5-hydroxytryptamine3 receptors in canine small intestine. Am J Physiol. 1992 Sep;263(3 Pt 1):G306–G311. doi: 10.1152/ajpgi.1992.263.3.G306. [DOI] [PubMed] [Google Scholar]
  12. Moreland R. S., van Breemen C., Bohr D. F. Mechanism by which serotonin attenuates contractile response of canine mesenteric arterial smooth muscle. J Pharmacol Exp Ther. 1985 Feb;232(2):322–329. [PubMed] [Google Scholar]
  13. 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]
  14. Van Nueten J. M., Janssen P. A., De Ridder A., Vanhoutte P. M. Interaction between 5-hydroxytryptamine and other vasoconstrictor substances in the isolated femoral artery of the rabbit; effect of ketanserin (R 41 468). Eur J Pharmacol. 1982 Feb 5;77(4):281–287. doi: 10.1016/0014-2999(82)90130-3. [DOI] [PubMed] [Google Scholar]

Articles from British Journal of Pharmacology are provided here courtesy of The British Pharmacological Society

RESOURCES