Reactive oxygen and nitrogen species in sepsis-induced hepatic microvascular dysfunction.
OBJECTIVE
Hepatic microvascular dysfunction is a critical event in the development of liver failure during sepsis. Activated blood cells and reactive oxygen and nitrogen species (RONS) have been implicated in the pathogenesis of sepsis.


METHODS
Intravital-videomicroscopy was used to determine whether RONS contribute to the recruitment of leukocytes/platelets in the hepatic microvasculature during sepsis. Six hours following cecal-ligation and puncture (CLP), disturbances of the hepatic microvasculature were assessed in WT-mice (C57Bl/6 J; n = 8), in mice lacking gp91(phox)(n = 5), overexpressing superoxide-dismutase (SOD, n = 8), in WT-mice treated with a NOS-inhibitor (L-NAME, n = 5), lacking nNOS, eNOS or iNOS (n = 5 each), treated with the NO-donor DetaNO (n = 5), in WT-mice treated with gadolinium-chloride (GdCl(2), n = 5) and compared to a group of WT-mice following a sham operation (n = 8). Six hours post-CLP, the adhesion of leukocytes and platelets in terminal hepatic venules (THV) and sinusoids was quantified.


RESULTS
In WT-mice, CLP elicited increases in the number of adherent leukocytes and platelets. Similar responses to CLP were noted in mice overexpressing SOD or lacking either eNOS or gp91(phox). The blood-cell recruitment was significantly blunted in septic iNOS-knockout mice and this response was reversed by pre-treatment with DetaNO.


CONCLUSIONS
These findings suggest that iNOS-derived NO is a determinant of the pro-inflammatory phenotype assumed by the hepatic microvasculature during sepsis.
Department of Pediatric Surgery, Medical University of Graz, Graz, Austria. georg.singer@medunigraz.at
Georg
G
Singer
Karen Y
KY
Stokes
D
D
Neil Granger
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001794:Blood Pressure; D002448:Cell Adhesion; D002452:Cell Count; D016207:Cytokines / Q000097:blood; D005682:Gadolinium / Q000494:pharmacology; D007958:Leukocyte Count; D008107:Liver Diseases / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology; D008297:Male; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000172:deficiency / Q000235:genetics; D019001:Nitric Oxide Synthase / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D010976:Platelet Count; D026361:Reactive Nitrogen Species / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000276:immunology*; D018805:Sepsis / Q000150:complications / Q000276:immunology* / Q000503:physiopathology; D013482:Superoxide Dismutase / Q000235:genetics
D016207:Cytokines; D008562:Membrane Glycoproteins; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D005682:Gadolinium; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D000410:Alanine Transaminase; C038958:gadolinium chloride