OBJECTIVETo investigate the biological activities of the bronchoalveolar lavage fluid (BALF) harvested from dogs with smoke inhalation injury at early post injury stage.

METHODSBALF was harvested from normal dogs and those inflicted by smoke inhalation injury for the employment in the study. Ninety four Wistar rats were employed in the study and were randomly divided into A (n=28), B (n=29) and C (n=37) groups. The rats were perfused intra-tracheally with normal saline, BALF from normal dog and BALF from injured dog, respectively in A, B and C groups. Every 7 rats in each group were used before the perfusion as normal control. The rats in control group and those in A, B and C groups at 4, 12 and 24 hours after BALF perfusion were sacrificed. The survival rate and the pathomorphological gross and microscopic changes in pulmonary tissue in all groups were observed. In addition, the contents of prostaglandin F1alpha/thromboxane B2 (PGF1alpha/TXB2), tumor necrosis factor (TNF-alpha) and myeloperoxidase (MPO) in pulmonary tissue homogenization and the pulmonary capillary permeability were determined simultaneously.

RESULTSAll the rats in A and B groups survived, but nine in C group died before sacrificing. The BALF from dogs inflicted by smoke inhalation injury could cause rat lung exhibiting pathomorphological changes similar to those in rats inhaling smoke directly. The rat pulmonary tissue contents of PGF1alpha/TXB2 in A and B groups after the perfusion tended to increase, while that in C group decreased gradually (P <0.01). The rat pulmonary tissue contents of TNF-alpha and MPO content in A and B groups after the perfusion revealed no obvious change (P >0.05), while those in C group increased evidently at 4 hour after the perfusion and decreased thereafter (P <0.05-0.01). The pulmonary capillary permeability in C group was higher than that in A and B groups at 4 hour after the perfusion (P < 0.01).

CONCLUSIONThe BALF from canine lungs during the early stage of inhalation injury exhibited biological activities. The primary and secondary pulmonary injury could be prevented or ameliorated by massive pulmonary lavage during early post injury stage after smoke inhalation injury.