| Objective Alveolar pneumocytes and vascular endothelial cell dysfunction and production of more oxygen free radicals play important roles in the pathogenesis of acute lung injury. Low potassium dextran glucose solution has been widely used clinically as an excellent lung preservation solution. It has cytoprotective effects on alveolar pneumocytes and endothelial cells, attenuates lipid peroxidation, and improves pulmonary graft function, so we hypothesized that systemic administration of low potassium dextran glucose solution via peripheral vein would have benefits in improving pulmonary function and affecting concentrations of some inflammatory cytokines after acute lung injury.Methods Acute lung injury was induced by intrapulmonary administration of 0.1 ml/kg of oleic acid in ten healthy experimental China mini-piglets (3.9kg-6.2kg,4-6 weeks, either sex). Animals were randomly assigned to two groups (n=5 each):control group with intravenous infusion of 12.5ml/kg of Lactated Ringer's solution via ear vein within 30 minutes before oleic acid administration, and intervening group with intravenous infusion of 12.5ml/kg of low potassium dextran glucose solution via ear vein within 30 minutes before oleic acid administration. The criterion for acute lung injury was defined as arterial partial pressure of oxygen to fraction of the inspired oxygen ratio (oxygenation index) less than 300mmHg. Arterial blood gas variables, hemodynamic variables, and plasmic concentrations of tumor necrosis factor-alpha, endothelin-1, soluble intercellular adhesion molecule-1, interleukin-10, interleukin 1-beta, and interleukin-6 were measured and recorded at baseline, the time at which acute lung injury occurred, and every one hour for 6 hours after initial lung injury.6 hours after lung injury, animals were sacrificed and lung specimens were taken for histologic analysis, evaluation of apoptosis, and measurement levels of tumor necrosis factor-alpha, endothelin-1, soluble intercellular adhesion molecule-1, and interleukin-10 in lung tissue supernatants.Results In intervening group, after acute lung injury, arterial blood pH (at six hours after initial injury,7.36±0.05 vs 7.09±0.03, P<0.01), arterial partial pressure of carbon dioxide were significantly lower than that in control group (P<0.05 or 0.01), while oxygenation index was significantly higher than that in control group (P<0.05). Mean pulmonary arterial pressure was significantly lower in intervening group than that in control group (at six hours after initial injury,21.4±5.0mmHg vs 39.2±0.8mmHg, P< 0.01). In intervening group, plasmic concentrations of soluble intercellular adhesion molecule-1 and endothelin-1 were significantly lower than that in control group (p< 0.05), while plasmic concentration of interleukin-10 was significantly higher than that in control group (P<0.05). Lung tissue damage was significantly slighter in intervening group than that in control group (for lung injury score 11.8±3.0 vs 19.2±3.8, P<0.0l). There was no significant difference in apoptosis cell counts between the two groups (10.6±1.3 cells/high power lens field vs 9.5±1.3 cells/high power lens field, P=0.086).6 hours after initial lung injury, level of tumor necrosis factor-alpha in lung tissue supernatant was significantly lower in intervening group than that in control group (4.98±0.62pg/ml vs 11.31±4.80pg/ml, P<0.05).Conclusions Premedication with systemic administration of low potassium dextran glucose solution via peripheral vein could improve gas-exchange function in lung, attenuate pulmonary hypertension, alleviate lung tissue damage, decrease plasmic concentrations of soluble intercellular adhesion molecule-1 and endothelin-1, increase plasmic concentration of interleukin-10, and decrease level of tumor necrosis factor-alpha in lung tissue in oleic acid-induced acute lung injury in juvenile piglets.
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