Perfluorochemical augmented rhSOD delivery attenuates inflammation in the immature lung

Abstract

Perfluorochemical (PFC) liquids have been shown to support lung function, uniformly distribute rhSOD and attenuate biomarkers of oxidative damage and inflammation in a juvenile model of acute lung injury. The impact of this approach on injury in the immature lung has not been evaluated. To test the hypothesis that intratracheal PFC augmented rhSOD delivery will attenuate lung injury, preterm lambs (n = 18; 123.4 ± 1.4 days gestation) were ventilated, and surfactant-treated. Lambs were then randomized to receive intratracheal rhSOD (5 mg/kg) in saline (n = 6) or PFC (n = 6), PFC (n = 3), or surfactant alone (n = 3) and studied for 4 hours. Cardiopulmonary parameters were monitored; lung IL-1β, IL-8, myeloperoxidase, SOD activity, lipid peroxidation, and lung morphology were assessed. Following surfactant treatment, oxygenation improved and remained stable in all groups. Compared to delivery in saline, PFC suspensions significantly increased the lung expansion index and SOD activity and reduced lung IL-1β, IL-8, myeloperoxidase, and isoprostane concentrations. These data demonstrate that PFC augmented rhSOD delivery attenuates inflammation in surfactant-treated immature lungs as compared to delivery in saline. We speculate that this enhanced protection may be related to PFC liquid facilitating rhSOD distribution and the mechanoprotective and cytoprotective properties of PFC liquids.