Does upregulation of inducible nitric oxide synthase (iNOS) render the stomach more susceptible to damage?

Antonio A. Castañeda, Jeremy W. Denning, Lily Chang, David W. Mercer

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Nitric oxide from constitutive nitric oxide synthase (NOS) augments gastric mucosal blood flow and is important in mucosal defense. However, the function of the inducible isoform of NOS (iNOS) in the gastric mucosa remains to be fully elucidated. This study was done to examine the role of iNOS in gastric mucosal blood flow and gastric injury following endotoxemia. Conscious rats were given intraperitoneal saline or lipopolysaccharide (LPS, 5 or 20 mg/kg). Five hours later, rats were anesthetized, a laparotomy made, gastric fluid aspirated, and 3 ml of 20% ethanol introduced into the forestomach. Hats were sacrificed 10 min later for assessment of macroscopic injury (mm2) to the gastric mucosa. Other rats did not receive 20% ethanol, but instead, gastric mucosal blood flow was determined with laser Doppler, followed by sacrifice and removal of stomachs for determination of gastric mucosal iNOS immunoreactivity (Western immunoblot). Lipopolysaccharide dose dependently increased gastric injury, decreased gastric mucosal blood flow, and increased gastric mucosal iNOS immunoreactivity compared to rats receiving saline. In additional experiments and using a similar protocol, intraperitoneal administration of aminoguanidine (45 mg/kg), an iNOS inhibitor, reversed lipopolysaccharide-induced gastric injury and restored gastric mucosal blood flow to baseline, whereas the nonselective NOS inhibitor, N(G)-nitro-L-arginine methyl ester (5 mg/kg) did not. Taken together, these data suggest that upregulation of iNOS is in part responsible for the detrimental effects of LPS on the gastric mucosa, possibly from a reduction in gastric mucosal blood flow.

Original languageEnglish (US)
Pages (from-to)174-179
Number of pages6
JournalJournal of Surgical Research
Volume84
Issue number2
DOIs
StatePublished - Jun 15 1999

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Nitric Oxide Synthase Type II
Stomach
Up-Regulation
Gastric Mucosa
Lipopolysaccharides
Wounds and Injuries
Nitric Oxide Synthase
Ethanol
Endotoxemia
NG-Nitroarginine Methyl Ester
Laparotomy
Nitric Oxide
Protein Isoforms
Lasers
Western Blotting

Keywords

  • Blood flow
  • Endotoxemia
  • Gastric injury
  • Nitric oxide synthase

ASJC Scopus subject areas

  • Surgery

Cite this

Does upregulation of inducible nitric oxide synthase (iNOS) render the stomach more susceptible to damage? / Castañeda, Antonio A.; Denning, Jeremy W.; Chang, Lily; Mercer, David W.

In: Journal of Surgical Research, Vol. 84, No. 2, 15.06.1999, p. 174-179.

Research output: Contribution to journalArticle

Castañeda, Antonio A. ; Denning, Jeremy W. ; Chang, Lily ; Mercer, David W. / Does upregulation of inducible nitric oxide synthase (iNOS) render the stomach more susceptible to damage?. In: Journal of Surgical Research. 1999 ; Vol. 84, No. 2. pp. 174-179.
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