Role of BALF from dogs with acute severe smoke inhalation injury in inducing lung injury of normal rats

Objective To investigate the existence, intensity and persisting time of biologic activity of bronchoalveolar lavage fluid (BALF) collected from dogs with acute severe smoke inhalation injury in early post injury stage. Methods BALF was collected 1 h after the establishment of acute severe sawdust smoke inhalation injury in 5 dogs, and the fluid was perfused into the lungs of Wistar rats in the amount of 5 ml/kg (group C). Normal saline (group A) and BALF from normal dog (group B) were perfused into the lungs of rats and served as control. The respiratory rate, PaO 2, lung water content and the expanding stability of lungs in all rats were determined at the time points of 4,12 and 24 h after the purfusion. Results Compared with the rats in group A and B, the rats in group C had higher mortality, wider range in RR, higher lung water content, PaO 2 decreased obviously and lower lung expanding stability. The rats in control groups showed slight mechanic obstruction in their airways in the course of experiment. Meanwhile,the rats in group C showed higher oxidative activities and lower total anti oxidative activities in lung tissues. Conclusion It is certain that the BALF collected from dogs with acute severe smoke inhalation injury in early post injury stage could induce obvious injury in lung structure of normal rats, showing certain mechanic obstruction in small airways. The injuring activity of the BALF can be alleviated ultimately 24 h after the perfusion of the BALF.