Systemic perfluorocarbons suppress the acute lung inflammation after gastric acid aspiration in rats

Perflurocarbons (PFCs) are used during Liquid ventilation and as hemoglobin substitutes. PFCs reduce free radical generation and damage to the lung du ring Liquid ventilation. Thus, we examined the effects of parenteral admini stration of PFCs on lung injury after acid aspiration. Rats were treated wi th intraperitoneal injection of either FC-77 or IV injection of Fluosol. Co ntrols received intraperitoneal or IV normal saline (NS) before or at the t ime of injury and then were injured by instillation of NS + HCl (pH = 1.25) into their lungs via a tracheotomy. The animals were exposed to air or 98% oxygen, breathing spontaneously. The rats were injected with 0.05 mu Ci of I-125-albumin (bovine serum albumin) before injury. The extent of lung inj ury was assessed 5 h postinjury by compliance and lung albumin permeability index measurement. Myeloperoxidase (MPO) activity and histologic examinati on were used to assess neutrophilic infiltration. Both FC-77 and Fluosol de creased the permeability index compared with controls (1.05 +/- 0.08: 1.08 +/- 0.12 respectively, versus 1.34 +/- 0.21) and improved lung compliance a fter intratracheal instillation of 1.2 mL/kg of HCl/NS, pH = 1.25 + hyperox ia injury (P < 0.05). Lung MPO activity decreased in the FC-77 group and wa s associated with a concomitant decrease in neutrophil infiltration. MPO ac tivity of the spleen increased after FC-77 treatment. The administration of FC-77 decreased the severity of lung permeability changes associated with acid in the presence or absence of hyperoxia exposure. These data suggest t hat attenuation of neutrophilic infiltration by PFCs decreases lung injury. Implications: Intraperitoneally administered perfluorocarbons in rats atte nuate the neutrophilic infiltration in the lung after acid aspiration, ther eby decreasing the alveolar protein leakage and improving pulmonary complia nce.