New Approaches for the Evaluation of Pulmonary Toxicity: Bronchoalveolar Lavage Fluid Analysis

New Approaches for the Evaluation of Pulmonary Toxicity: BronchoalveolarLavage Fluid Analysis. Henderson, R. F., BENSON, J. M., HAHN,F. F., HOBBS, C. H., JONES, R. K., MAUDERLY, J. L., MCCLELLAN,R. O., AND PICKRELL, J. A., (1985). Fundam. Appl. Toxicol. 5,451–458. Analysis of bronchoalveolar lavage fluid (BAL)is an effective method of detecting an inflammatory responsein the lungs of animals in toxicological studies. Alterationsin BAL that are the most sensitive indications of an inflammatoryresponse are an increased content of serum proteins and an influxof neutrophils (PMNs). Elevation of the cytoplasmic enzyme lactatedehydrogenase (LDH) is a useful indicator of cytotoxicity. Thepulmonary inflammatory response to particles (either mineraldusts or soot) in the lung includes greatly increased activitiesof such lysosomal enzymes as ß-glucuronidase and ß-N-acetylglucosaminidasein BAL. Examination of alterations in BAL in rats and mice duringchronic exposure to high levels of diluted diesel exhaust revealedthat steadily increasing levels of LDH, ß-glucuronidase,and hydroxyproline in BAL correlated better with the developmentof pulmonary fibrosis than did measures of an inflammatory response(protein, PMNs). Analysis of BAL has proven useful, both fordetection of lung injury in toxicological screening tests andfor determination of the mechanisms of developing chronic lungdisease. Future work shows promise of developing assays forBAL analysis to identify the specific site or type of pulmonaryinjury present