Calcium-antagonistic activity of sumatriptan in the rat anococcygeus muscle


Emre-Aydingoz S., Kocaefe C. , Tuncer M.

PHARMACOLOGY, vol.64, no.1, pp.43-48, 2002 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 64 Issue: 1
  • Publication Date: 2002
  • Doi Number: 10.1159/000056149
  • Title of Journal : PHARMACOLOGY
  • Page Numbers: pp.43-48

Abstract

The relaxant effect of sumatriptan, a 5-HT1B/1D receptor agonist, on the rat anococcygeus muscle was investigated. Sumatriptan induced concentration-dependent relaxations of the phenylephrine-precontracted rat anococcygeus muscle. N-G-nitro-L-arginine, methylene blue, glibenclamide, tetrodotoxin, indomethacin, GR 113808, GR 55562, methysergide, ketanserin, ICS 205930, clozapine, methiothepin, metergoline, mesulergine, and ritanserin did not inhibit the relaxations induced by sumatriptan. Sumatriptan converted calcium-induced contractions into relaxations in the preparations depolarized by a calcium-free, high-potassium solution. In membrane preparations obtained from the rat anocoecygeus muscle, the basal rate of cAMP production by adenylate cyclase was 4.77 +/- 0.02 pmol/mg protein/min (n = 15). The enzyme activity was increased to 104 +/- 51.7 pmol/mg protein/min by forskolin (10(-4) mol/l), but did not change in the presence of sumatriptan. The mRNA expression of 5-HT1B, 5-HT1D, and 5-HT7 receptors was not observed in the rat anococcygeus muscle. The results indicate that sumatriptan causes relaxation of the precontracted rat anococcygeus muscle by a calcium-antagonistic activity. Copyright (C) 2002 S. Karger AG, Basel.