Vaporized Perfluorocarbon Confers Protection Against Acute Lung Injury by Inhibiting MMP-9 Expression without Protective Effects in Other Organs

OBJECTIVE: Vaporized perfluorocarbon (PFC) is a treatment for lung injury; this study investigated its mode of action and potential protective effects on other organs, which are unclear. METHODS: Acute lung injury was induced by lung lavage with artificial seawater in 32 female New Zealand White rabbits. Animals received either conventional mechanical ventilation (CMV), positive end-expiratory pressure under CMV (PEEP), vaporized PFC ventilation, or positive end-expiratory pressure with vaporized PFC ventilation (PEEP + PFC). Histopathology of the lung, small intestine, liver and kidney were investigated. Matrix metalloproteinase (MMP)-9 mRNA levels in the lung were analysed. RESULTS: Pathological injury of the lung was significantly alleviated in the PEEP, PFC and PEEP + PFC groups compared with the CMV group. Tissue damage in the liver, kidney and small intestine was similar between all groups. MMP-9 mRNA levels in the PEEP, PFC and PEEP + PFC groups were significantly lower than those in the CMV group. CONCLUSIONS: Vaporized PFC ventilation can significantly alleviate lung injury but has no significant protective effect on other organs. Alleviation of lung injury may be associated with MMP-9 inhibition.