Induced nitric oxide promotes intestinal inflammation following hemorrhagic shock.
In hemorrhagic shock (HS), increased cytokine production contributes to tissue inflammation and injury through the recruitment of neutrophils [polymorphonuclear cells (PMN)]. HS stimulates the early expression of inducible nitric oxide synthase (iNOS) that modulates proinflammatory activation after hemorrhage. Experiments were performed to determine the contribution of iNOS to gut inflammation and dysmotility after HS. Rats subjected to HS (mean arterial pressure 40 mmHg for 2.5 h followed by resuscitation and death at 4 h) demonstrated histological signs of mucosal injury, impairment of intestinal smooth muscle contractility, extravasation of PMN, and increased gut mRNA levels of ICAM-1, IL-6, and granulocyte colony-stimulating factor (G-CSF). In addition, DNA binding activity of NF-kappaB and Stat3, an IL-6 signaling intermediate, was significantly increased. In shocked rats treated with the selective iNOS inhibitor l-N(6)-(1-iminoethyl)lysine at the time of resuscitation, histological signs of intestinal injury and PMN infiltration were reduced and muscle contractility was almost completely restored. Selective iNOS inhibition in shocked animals reduced the binding activity of NF-kappaB and Stat3 and reduced mRNA levels of ICAM-1, IL-6, and G-CSF. The results of studies using iNOS knockout mice subjected to HS were similar. We propose that early upregulation of iNOS contributes to the inflammatory response in the gut wall and participates in the activation of signaling cascades and cytokine expression that regulate intestinal injury, PMN recruitment, and impaired gut motility.
Hierholzer
Christian
C
Department of Surgery, University of Pittsburgh Medical Center, F1264-200 Lothrop St., Pittsburgh, PA 15213, USA.
Kalff
Jörg C
JC
Billiar
Timothy R
TR
Bauer
Anthony J
AJ
Tweardy
David J
DJ
Harbrecht
Brian G
BG
D000818:Animals; D016207:Cytokines / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004751:Enteritis / Q000209:etiology* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005769:Gastrointestinal Motility; D045823:Ileus / Q000209:etiology / Q000503:physiopathology; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007583:Jejunum / Q000201:enzymology / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008239:Lysine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D051379:Mice; D018345:Mice, Knockout / Q000235:genetics; D016328:NF-kappa B / Q000378:metabolism; D020556:Neutrophil Infiltration; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D051381:Rats; D017207:Rats, Sprague-Dawley; D050796:STAT3 Transcription Factor; D012771:Shock, Hemorrhagic / Q000150:complications*; D015534:Trans-Activators / Q000378:metabolism
D016207:Cytokines; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; C090663:N(6)-(1-iminoethyl)lysine; D016328:NF-kappa B; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; C494088:Stat3 protein, rat; D015534:Trans-Activators; D018799:Intercellular Adhesion Molecule-1; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C496318:Nos2 protein, rat; D008239:Lysine