Effects Of Perfluorocarbon Aerosol Inhalation On The Lung Surfactant And Surfactant Protein A And TNF-α Levels In Rats Of Acute Lung Injury Induced By Lipopolysaccharide

Objective To investigate the effects of inhalation of perfluorocarbon (PFC) aerosol on lung surfactant, surfactant protein A (SP-A) and TNF-αin rats with acute lung injury.Methods Selection 32 healthy adult rats, each weighed 250-300g. Acute lung injury was induced by intraperitoneal injection of lipopolysaccharide (LPS,8mg/kg). One hour after LPS injection, PFC aerosol was inhalated for 20 minutes. The results were compared with the group, in which normal saline was used insead of LPS as the control. Eight hours after LPS injection the effects of PFC inhalztion on the artery blood gas, death incidence, and dipalmitoylphosphatidylchloline, SP-A, TNF-a and lung surfactant concentrations in bronchoalveolar lavage fluid (BALF) were measured by using ELISA or HPLC.Results After the inhalation of PFC, PaO2 increased significantly with relatively lower PaCO2 and death incidence in rats following acute lung injury than that in the group received NS inhalation (P＜0.01). Compared with the NS inhalation group, concentrations of SP-A and dipalmitoylphosphatidylchloline, the major component of lung surfactant in the BALF were higher (P<0 01), with a lower BALF concentration of TNF-a in PFC inhalation group (P<0 01). 1. The basic values of PaO2 and PaCO2 in each group of rats were normal and the difference was not statistically significant. Compared with the baseline, PaO2 decreased significantly (PaO2/FiO2<200) in group LPS-NS and LPS-PFC. Compared with the group LPS-NS, PaO2 increased, but PaCO2 decreased in group LPS-PFC; the ratio of mortality rates between group LPS-NS and LPS-PFC was 8:3 and the difference was statistically significant (P<0.01).2. Compared with the group NS-NS, lung alveolar epithelial cell damage, capillary obstruction, pulmonary interstitial edema, inflammatory cell infiltration could be observed in rats of group LPS-NS. The lung injury score was 3 which increased significantly. Compared with group LPS-NS, the lung injury score of group PFC aerosol inhalation was 1 which was significantly lower and the difference was statistically significant (P<0. 01).3. There were no difference of the W/D ratio of lung tissue between group NS-NS and LPS-NS. Compared with the group LPS-NS, the W/D ratio of lung tissue in group LPS-PFC was decreased and the difference was statistically significant(P<0.01).4. There were no difference of the RBC, PMN and AM counts between group of NS-NS and LPS-NS. The RBC, PMN and AM counts were statistically decreaesd in the group LPS-PFC compared with the group LPS-NS (P<0.01). 5. Compared with the group NS-NS, TNF-a and TP concentrations in BALF were significantly increased, and the SP-A, DPPC concentration were decreased in group LPS-NS (P＜0.05). While in group LPS-PFC, TP concentrations and TNF-a in BALF were significantly reduced, and SP-A and DPPC were significantly increased compared with the group LPS-NS (P<0.05).Conclusion Inhalation of PFC aerosol during the LPS-induced acute lung injury of rats can increase SP-A and surfactant concentration and decrease TNF-a concentration in BALF, which possibly be useful for the treatment of acute lung injury.