Enhanced lung toxicity of intratracheally instilled cadmium chloride in selenium-deficient rats

In order to further characterize biochemical correlates of CdCl₂-induced lung injury, CdCl₂ lung toxicity was studied in Se-deficient rats. A solution of 0.5 μmol/kg of CdCl₂ was intratracheally instilled into chronic respiratory disease-free 70-day-old rats fed a basal Se-deficient diet or a basal diet supplemented with 0.5 or 2.0 ppm of Se for 40 days. Within 3 days Se-deficient rats showed signs of marked respiratory distress and 25% had died, whereas rats from Se-supplemented groups all survived this time period. As evidenced by gross examination and lung water contents, Se-deficient rats exhibited a greater degree of inflammatory pulmonary edema than did rats from Se-supplemented groups. The results of the various enzymatic and biochemical determinations may be interpreted as being consistent with greater damage occurring in the Se-deficient rats.