Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Lipopolysaccharide (LPS) or endotoxin can induce Toll-like receptor 4 signaling and cause microcirculatory dysfunction, which can lead to multiple organ dysfunction. The goal of this study was to investigate whether Toll-like receptor 4 antagonist, eritoran tetrasodium, can attenuate microcirculatory dysfunction in endotoxemic rats. Seventy-two male Wistar rats were divided into three groups as follows: control, LPS, and eritoran + LPS. ⋯ Eritoran also attenuated endotoxin-induced elevation in the serum level of D-dimer. In conclusion, we have established a promising rat protocol to investigate the intestinal microcirculation in endotoxemia. Our data indicate that eritoran can reduce microcirculatory dysfunction in endotoxemic rats.
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The formation of oxidative stress in the lung and activation of neutrophils are major determinants in the development of respiratory failure after acute lung injury and sepsis. However, the time changes of these pathogenic factors have not been sufficiently described. Twenty-four chronically instrumented sheep were subjected to cotton smoke inhalation injury and instillation of live Pseudomonas aeruginosa into both lungs. ⋯ In addition, progressive increases in markers of neutrophil accumulation in the lung were observed. The peak of neutrophil accumulation in the lung was associated with a severe depletion of circulating neutrophils. The results from our model may enhance the understanding of the pathophysiological alterations after acute lung injury and sepsis and thus be useful in exploring therapeutic interventions directed at modifying the expression or activation of inflammatory mediators.
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Endotoxin tolerance is a well-studied phenomenon associated with a reduced inflammatory response. In the switch from an inflammatory to an anti-inflammatory response in clinical sepsis, the concept of endotoxin tolerance is of obvious interest. However, only limited data exist regarding the effect of endotoxin tolerance on organ dysfunction, and therefore, this was investigated in a porcine intensive care sepsis model. ⋯ The inflammatory responses as well as parameters representing circulation, hypoperfusion, and cardiac and renal function were all markedly attenuated in animals pre-exposed to endotoxin and intensive care as compared with animals not pre-exposed. In animals pre-exposed to endotoxin and given the high-dose of endotoxin challenge, deterioration in pulmonary function was equal to or even worse than in animals not pre-exposed. In contrast to the overall protective effect of endotoxin tolerance observed in other organ systems, the lungs of endotoxin-tolerant animals demonstrated an increased responsiveness to high-dose endotoxin challenge.
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Acute lung injury (ALI) is still a leading cause of morbidity and mortality in critically ill patients. Recently, our and other studies have found that hydrogen gas (H₂) treatment can ameliorate the lung injury induced by sepsis, ventilator, hyperoxia, and ischemia-reperfusion. However, the molecular mechanisms by which H₂ ameliorates lung injury remain unclear. ⋯ In addition, i.p. injection of 10 mL/kg hydrogen-rich saline also significantly attenuated the LPS-induced ALI. Collectively, these results demonstrate that molecular hydrogen treatment ameliorates LPS-induced ALI through reducing lung inflammation and apoptosis, which may be associated with the decreased NF-κB activity. Hydrogen gas may be useful as a novel therapy to treat ALI. munosorbent assay; H₂-hydrogen gas; HMGB1-high-mobility group box 1; HS-hydrogen-rich saline; i.t.-intratracheal; KC-keratinocyte-derived chemokine; LPS-lipopolysaccharide; MCP-1-monocyte chemoattractant protein 1; MIP-1α-macrophage inflammatory protein 1α; MIP-2-macrophage inflammatory protein 2; MPO-myeloperoxidase; PBS-phosphate-buffered saline; PMNs-polymorphonuclear neutrophils; TUNEL-deoxynucleotidyl transferase dUTP nick end labeling; W/D-wet-to-dry.
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The aim of the current study was to determine whether hypercholesterolemia affects the delayed sevoflurane preconditioning against myocardial ischemia-reperfusion (IR) injury and, if so, the underlying mechanism. Male Sprague-Dawley rats fed 2% cholesterol-enriched chow for 8 weeks were subjected to sevoflurane preconditioning (2.4% vol/vol, 1 h) 24 h before myocardial ischemia was induced by occluding the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min. The hemodynamic parameters left ventricular developed pressure, left ventricular end-diastolic pressure, and maximal rise/fall rate of left ventricular pressure were continuously monitored, and myocardial infarct size was determined at the end of reperfusion. ⋯ The expression of endothelial NOS and Bad did not differ among all groups. The expression of myocardial phosphorylated endothelial NOS, Bcl-2, and phosphorylated Bad in normocholesterolemic rats was not affected by delayed sevoflurane preconditioning but was decreased in the hypercholesterolemic control group, and this was not reversed by sevoflurane, compared with the normocholesterolemic control group. Taken together, these results indicate that sevoflurane preconditioning exerts delayed cardioprotection against IR injury in normocholesterolemic rats, which is blocked by hypercholesterolemia potentially via interference with the iNOS/mitochondrial ATP-dependent K⁺ channel pathway.