Dobutamine enhances alveolar fluid clearance in a rat model of acute lung injury.

Acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), remain leading factors for morbidity and mortality in critically ill patients. A significant aspect of ALI and ARDS is impaired alveolar fluid clearance (AFC). Improvements in therapies for these types of respiratory illnesses will require an understanding of the mechanisms that control AFC. The present study was designed to determine whether the administration of dobutamine decreases pulmonary edema and stimulates AFC in a rat model of lipopolysaccharide-induced lung injury. Adult male Sprague-Dawley rats were randomly divided into three groups: control, lipopolysaccharide, and lipopolysaccharide + dobutamine. The effect of dobutamine on AFC and the expression of aquaporin-1 and aquaporin-5 were examined. Lipopolysaccharide administration results in significant lung injury with impaired AFC, while dobutamine improves alveolar fluid reabsorption with elevation of aquaporin-1 and aquaporin-5. Our study indicates that dobutamine may enhance alveolar fluid reabsorption by increasing the expression of aquaporin-1 and aquaporin-5.