Figure 4

Effects of OxPAPC on high tidal volume (HTV)-induced lung vascular leak. Mice were treated with OxPAPC (1.5 mg/kg, intravenous) or DMPC (1.5 mg/kg, intravenous) followed by mechanical ventilation at low tidal volumes (LTVs) (7 mL/kg) or HTVs (30 mL/kg) for 4 hours. Effects of phospholipids on the HTV-induced vascular leak were assessed by measurements of Evans blue leakage into the lung tissue. HTV, but not LTV, induced Evans blue leakage from the vascular space into surrounding lung tissue, which was dramatically attenuated by OxPAPC (a), but not by DMPC (b), pretreatment. The results are representative of three independent experiments. Insets depict the quantitative analysis of Evans blue-labeled albumin extravasation in the shown lung preparations, which was performed by spectrophotometric analysis of Evans blue extracted from the lung tissue samples as described in Materials and methods. Evans blue accumulation in the lungs from HTV-exposed animals (122 ± 12 μg/g wet weight lung tissue) was taken as 100%. The results are representative of three independent experiments. DMPC, di-myristoyl-sn-glycero-3-phosphorylcholine; OxPAPC, oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine.