EARLY DAMAGE INDICATORS IN THE LUNGS .4. BIOCHEMICAL AND CYTOLOGIC RESPONSE OF THE LUNG TO LAVAGE WITH METAL-SALTS

A rapid screening test for estimating the acute toxicity level of substances in the lung has been developed and evaluated using metal salts as the toxic agents. In the test, animals were exposed in vivo to the metal salts by bronchopulmonary lavage, and toxicity was determined by the enzymatic and cytologic response observed in the airways 1 day after exposure. The airway response was determined by analysis of bronchopulmonary lavage fluid for lactate dehydrogenase, acid and alkaline phosphatase, and β-glucuronidase activity as well as for total sialic acid and protein content and total and differential cell counts. These values showed a dose-dependent response in the lavage fluid. The enzymatic response of the lung tissue itself was not as marked as that seen in the lavage fluid. Histopathological evaluations of lung tissue were made in order to correlate morphological change with the airway response. The test allowed a rapid determination of the lung dose of metal salt which caused acute toxicity. Based on the biochemical response in the airway, the relative toxicity of the heavy-metal-containing compounds tested was: CdCl2>SeO2, NH4VO3, NiCl2>CrCl3. © 1979.