Objective To investigate the effects and mechanisms of pentoxifylline ( PTX )pretreatment on acute lung injury ( ALI) induced by hemorrhagic shock in mice. Methods Ninety mice were randomly divided into three groups, ie. a control group, a hemorrhagic shock group, and a PTX group.Lung histological changes were examined by HE staining. Meanwhile, the wet-to-dry weight ratio ( W/D) and myeloperoxidase ( MPO) activity in lung were measured. The levels of TNF-αand IL-1βin lung homogenatewere measured by ELISA. The expressions of TLR4 mRNA and TLR4 protein in lung were detected by reverse transcription-polymerase chain reaction ( RT-PCR ) and Western blot, respectively. Results Hemorrhagic shock induced obvious ALI changes in lungs of the hemorrhagic shock group. W/D and MPO activity were significantly higher in the hemorrhagic shock group than the control group( P lt; 0. 01) . The expressions of TNF-α, IL-1β, TLR4 mRNA and TLR4 protein were also significantly higher than the control group( P lt;0. 01) . PTX pretreatment could relieve ALI changes induced by hemorrhagic shock, and decrease W/D and MPO activity. The expressions of TNF-α, IL-1β, TLR4 mRNA and TLR4 protein were also decreased by PTX pretreatment. Conclusions PTX pretreatment shows protective effects on ALI afterhemorrhagic shock. Its possible mechanismmay relate to down-regulation of TLR4, thus inhibit the expression of pro-inflammatory cytokins.
