Effect of hydroxyl radical (OH) on sphincter of oddi motility

Joseph J. Cullen, Amber Ledlow, Joseph A. Murray, Jeffrey L. Conklin

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

Antioxidant enzymes are present in sphincter of Oddi nerves and regulate sphincter of Oddi motor function mediated by NO-releasing nerves. Oxygen free radicals (O./2) produce hydrogen peroxide (H2O2) by the action of superox-ide dismutase (SOD). Hydroxyl radical (OH) has been shown to play an important role as a mediator of H2O2 toxicity. The aims of our study were to determine the effects of H2O2 on sphincter of Oddi motility and if these effects are mediated by OH. Adult opossums were sacrificed and the sphincter of Oddi removed and placed in a tissue bath containing oxygenated Krebs solution. Force transducers recorded tension in a transverse orientation at two sites along the sphincter of Oddi specimen. H2O2 was added into the tissue bath at concentrations from 0.01 to 0.5%. O2 radicals were inhibited by the addition of SOD, while OH was scavenged by the addition of alcohol (ETOH) or dimethyl sulfoxide (DMSO). H2O2 produced a dose-dependent increase in baseline amplitude, frequency, and peak amplitude of contractions. The effect of 0.01% H2O2 on sphincter of Oddi contractile frequency was inhibited by 0.2% ETOH and DMSO, but not by SOD. We conclude that H2O2 has profound effects on sphincter of Oddi motility and that the actions of H2O2 are probably mediated through OH.

Original languageEnglish (US)
Pages (from-to)452-457
Number of pages6
JournalDigestion
Volume58
Issue number5
DOIs
StatePublished - Jan 1 1997

Keywords

  • Free radicals
  • Motility, Oddi’s muscle
  • Sphincter of Oddi

ASJC Scopus subject areas

  • Gastroenterology

Fingerprint Dive into the research topics of 'Effect of hydroxyl radical (OH) on sphincter of oddi motility'. Together they form a unique fingerprint.

  • Cite this