Active Na+ transport by alveolar epithelial cells has been demonstrated to contribute significantly to alveolar fluid clearance. However, the contribution of transepithelial Cl− movement to the reabsorption of isosmotic fluid across the alveolar epithelium in vivo has not been elucidated. We hypothesized that Cl− transport could be increased across the alveolar epithelium in vivo and across cultured alveolar type II cells by agents that increase intracellular cAMP (e.g., forskolin). In studies where 5% albumin in sodium methanesulfonate (a Cl−-free solution) was administered into the lung, forskolin administration significantly increased intracellular influx of Cl− and fluid into the alveolar space. In vitro studies with cultured rabbit alveolar type II cell monolayers in Ussing chambers demonstrated that elevations in intracellular cAMP increase short-circuit current by increasing both Cl−secretion and Na+ reabsorption. The cystic fibrosis transmembrane conductance regulator channel blocker glibenclamide and the loop diuretic bumetanide partially decreased the forskolin-induced increase in short-circuit current. These data may explain the failure of agonist that stimulated intracellular cAMP to increase alveolar fluid clearance in the rabbit. Moreover, the data suggest that in the event Na+absorptive pathways are damaged, transepithelial Cl− secretion and the consequent intra-alveolar fluid influx may be upregulated.

Rabbits may serve as a model of hemostasis that closely approximates human situations to mechanistically determine the etiology of coagulopathy. The contribution of platelet function to total clot strength is similar to that observed in humans.

We conclude that multiple organ injury and xanthine oxidase release after hepatoenteric ischemia-reperfusion are decreased by colloid administration.