Effects of nebulized heparin on pulmonary inflammation in a rat model of acute lung injury

Introduction: Sepsis is a mayor cause of acute respiratory distress syndrome (ARDS). In sepsis, the anticoagulant system is impaired. Nebulization of anticoagulants might allow for higher pulmonary concentration and reduce the risk of systemic bleeding. Objectives: To assess the effects of nebulized heparin in a rat model of acute lung injury. Methods: Adult male Sprague-Dawley rats (250-300 g; n=8/group) were subjected to intratracheal administration (IA) of LPS (10 μg/g b.w.). Saline or heparin (1000 IU/kg) were nebulized at 4 and 8h after LPS instillation. Animals were sacrificed 24h after the injury. Inflammatory cells and total proteins were assessed in bronchoalveaolar lavage fluid (BALF). IL-6, GROKC and TNFA were measured in lung homogenate by multiplex assay. Data are reported as mean±SD. One-way ANOVA was used for multigroup comparisons. Results: In BALF, nebulized heparin significantly reduced neutrophils in animals instilled with LPS (12±4x107 cells/ml) compared to animals administrated with LPS and nebulized with saline (18±6x107 cells/ml, p Conclusions: Our results showed that nebulized heparin administration reduced pulmonary inflammatory response in a rat model of acute lung injury.