Lipopolysaccharide temporarily impairs sphincter of Oddi motility.
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.
Cullen
J J
JJ
Department of Surgery, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA. joseph-cullen@uiowa.edu
Park
H
H
Ephgrave
K S
KS
Conklin
J L
JL
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
D017931:DNA Primers; D008070:Lipopolysaccharides; D017942:Nitric Acid; D019001:Nitric Oxide Synthase