Title: Hypertonic resuscitation of hemorrhagic shock prevents alveolar macrophage activation by preventing systemic oxidative stress due to gut ischemia/reperfusion Powers KA, Zurawska J, Szaszi K, Khadaroo RG, Kapus A, Rotstein OD Ref: Surgery, 137:66, 2005 : PubMed
BACKGROUND: The gut is a target organ of shock/resuscitation (S/R); however, it also contributes to distant inflammation through the generation of oxidants. S/R with antioxidants such as N-acetylcysteine (NAC) prevents lipopolysaccharide (LPS)-induced cytokine production and NF-kappaB activation in rat alveolar macrophages. Therefore, we hypothesized that hypertonic saline (HTS) might exerts its protective effect by preventing gut ischemia/reperfusion injury, thus decreasing oxidative stress and distant priming in alveolar macrophages. METHODS: A two-hit rat model of shock resuscitation was used. Plasma levels of 8-iso-prostaglandin, a marker of lipid peroxidation, was quantified by eicosanoid immunoassay with acetylcholinesterase kit. Gut histology with hematoxylin and eosin staining was performed 1 to 6 hours after resuscitation. Alternatively, alveolar macrophages from bronchoalveolar lavage (BAL) at end resuscitation were incubated in vitro with LPS (0.01 mug/mL), and NF-kappaB translocation was observed by immunofluorescent staining with anti-p65 antibody. RESULTS: HTS resuscitation prevented leukosequestration in the alveolar space, and it abrogated the progressive rise in blood 8-iso-prostaglandin production observed with Ringer's lactate (RL) resuscitation. Inhibition of oxidant stress with NAC corresponded with the ability of HTS to prevent S/R-induced edema, villus flattening, and mucosal sloughing in the mid-ileum. LPS-induced NF-kappaB translocation in alveolar macrophages after RL was 42% compared to 20% after HTS. Similar attenuation was observed with NAC resuscitation (16%). CONCLUSIONS: HTS resuscitation prevents systemic oxidative stress by reducing gut ischemia/reperfusion injury and consequently attenuates distant alveolar macrophage priming, thereby reducing LPS-induced NF-kappaB nuclear translocation in alveolar macrophages and organ injury. This represents a novel mechanism whereby HTS exerts its immunomodulatory effects.
        
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Powers KA, Zurawska J, Szaszi K, Khadaroo RG, Kapus A, Rotstein OD (2005) Hypertonic resuscitation of hemorrhagic shock prevents alveolar macrophage activation by preventing systemic oxidative stress due to gut ischemia/reperfusion Surgery137: 66-74
Powers KA, Zurawska J, Szaszi K, Khadaroo RG, Kapus A, Rotstein OD (2005) Surgery137: 66-74