title: Lipopolysaccharide temporarily impairs sphincter of Oddi motility.
abstract: The aim of our study was to determine the effect of lipopolysaccharide (LPS) on sphincter of Oddi (SO) motility. Opossums received saline, Escherichia coli LPS (1.0 mg/kg), or E. coli LPS (1.0 mg/kg) and aminoguanidine (50 mg/kg), and the SO was removed 6-24 h later. At 12 h LPS decreased electrical field stimulation (EFS)-induced relaxation and increased baseline tone. These changes were reversed when the animals were pretreated with aminoguanidine. The dose-dependent decrease in EFS-induced relaxation by N(omega)-nitro-l-arginine was impaired after LPS, but not in animals that received LPS and aminoguanidine. The impaired EFS-induced relaxation after LPS was reversed when l-arginine was added to the tissue bath. Serum levels of NO(-)(2)/NO(-)(3) were increased with LPS as compared to saline or both LPS and aminoguanidine. Inducible nitric oxide synthase mRNA was readily seen in SO segments after LPS. LPS impairs EFS-induced relaxation and increases baseline tone of the SO. The effects of LPS on SO motility appear to be mediated by nitric oxide.
authors.affiliation: Department of Surgery, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA. joseph-cullen@uiowa.edu
authors.forename: J J
authors.initials: JJ
authors.lastname: Cullen
authors.forename: H
authors.initials: H
authors.lastname: Park
authors.forename: K S
authors.initials: KS
authors.lastname: Ephgrave
authors.forename: J L
authors.initials: JL
authors.lastname: Conklin
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004558:Electric Stimulation; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D017942:Nitric Acid / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000235:genetics; D009893:Opossums; D009803:Sphincter of Oddi / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000502:physiology
chemical_list: D017931:DNA Primers; D008070:Lipopolysaccharides; D017942:Nitric Acid; D019001:Nitric Oxide Synthase