Experimental Study Of Lung Injury With Delayed Fluid Resuscitation After Severe Scold In Rats At High Altitude

Objective To evaluate lung injury and its mechanism after severe scold with delayed fluid resuscitation in rats at different altitude.Methods A total of 240 male Wistar rats were checked as objects of this study. They were randomly divided into 3 groups at different altitudes(1517m and 3848m): delayed fluid resuscitation group(DFR),immediate fluid resuscitation group(IFR) and control group(CG).The models of third degree scold would occupied thirty percent of total body surface were established.The lung samples were harvested at 1, 6,12,24,72 and 168 h after scold respectively.Pathological techque,tissue microarry, immunohistochemistry,image analysis techniques were employed to detect pathological changes of lung,alveolar cells apoptosis,protein expressions of BCL-2,HIF-1α,P53,NF-κB,TRAIL and their relationship.Results①With altitude height rising,alveolar wall increased thickness strikingly,capillary endothelial cells swelled,edeuca fluid appeared,in alveolar cavity,and inflammatory cells.The significant differences appeared between DFR and IFR,which expression level of alveolar epithelial cell were much higher in DFR and IFR than that in CG,at 3840m altitude than those at 1517m,and in DFR than those in IFR(P＜0.05).②The positive expression of BCL-2,HIF-1α,P53,NF-κB appeared in nucleus and cytoplasmic.The expression level of BCL-2,HIF-1α,P53,NF-κB were much higher in DFR and IFR than those in CG,at 3840m altitude than those at 1517m,and in DFR than those in IFR(P＜0.05).③The positive expression of TRAIL appeared in cytoplasmic and cell membrane.. The expression level of alveolar epithelial cell were much higher in DFR and IFR than those in CG,at 3840m altitude than those at 1517m,and in DFR than those in IFR(P＜0.05).④There were significant positive correlation between cell apoptosis and expression of BCL-2,HIF-1α,TRAIL(r=0.872,0.945,0.969,P＜0.05).Conclusion①With altitude height rising,there were obviously differences of pathological changes of lung after severe scald with delayed fluid resuscitation.②The lung apoptosis cell number was increased after severe scold with delayed fluid resuscitation at high altitude.③HIF-1α,P53 and NF-κB may participate in lung injury after severe scold with delayed fluid resuscitation in rats at different altitude.④BCL-2 and HIF-1αplay a regulative role in cell apoptosis in lung appear of severe scold rats at different altitude.⑤TRAIL apoptosis pathway may participate in the induction of apoptosis of lung cells after severe scold with delayed fluid resuscitation in rats at different altitude.