Contractile effect of platelet-activating factor on isolated duodenal smooth muscle

Yildirim G., Koç E., Zaloglu N.

Medical Science Research, vol.28, no.1, pp.13-15, 2000 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 28 Issue: 1
  • Publication Date: 2000
  • Journal Name: Medical Science Research
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.13-15
  • Keywords: Duodenum, Platelet-activating factor, Smooth muscle contractility
  • Ankara University Affiliated: Yes

Abstract

Platelet-activating factor (PAF) acts as a lipid mediator in allergic and inflammatory reactions. We have investigated its effect on isolated rat duodenal smooth muscle and measured the isometric contractions (n = 13). PAF-induced contraction was as potent as that observed with acethylcholine (ACh). Pre-incubation with ketanserin did not prevent the contractile effect of PAF/ACh. Atropine blocked the contractile effect of ACh but did not alter the effect of PAF. Therefore parasympathetic activation and serotonin release mechanisms do not explain the mechanisms by which PAF caused isolated rat duodenal smooth muscle to contract. Diltiazem completely inhibited the PAF-induced contraction. These results support the hypothesis that PAF contracts isolated duodenal smooth muscle directly through a specific PAF receptor. They also indicate that the PAF-induced contractile response at rat duodenal smooth muscle is due to an influx of Ca2+ through voltage-dependent and receptor-operated Ca2+ channels. (C) 2000 Science Reviews.