Pulmonary effects of acute vanadium pentoxide inhalation in monkeys.

An experimental study was conducted to investigate the hypothesis that changes in pulmonary function induced by vanadium pentoxide (V2O5) inhalation would be accompanied by evidence of pulmonary inflammation. Sixteen adult, male cynomolgus monkeys were acutely exposed by whole-body inhalation of V2O5 dust at aerosol concentrations of 0.5 mg V2O5/m3 and 5.0 mg V2O5/m3, conducted at a 1-wk interval. Comprehensive pulmonary function tests were performed 1 day after each inhalation exposure to detect functional changes in the airways and pulmonary parenchyma. Pulmonary inflammation was assessed by cytologic analysis of respiratory cells recovered from the lower respiratory tract by bronchoalveolar lavage (BAL). Postexposure values for pulmonary function and BAL were compared with the baseline values determined for each monkey prior to V2O5 exposure. Acute V2O5 dust inhalation produced significant air-flow limitation in both central and peripheral airways without producing any detectable changes in parenchymal function. These functional changes were accompanied by a significant increase in the total cell counts recovered from the lungs by BAL. The increase in total cell count occurred through a dramatic increase in absolute number and relative percentage of polymorphonuclear leukocytes (PMN). These findings suggest that pulmonary inflammatory changes involving PMN may play an important role in the occurrence of air-flow limitation after acute inhalation of V2O5 dust.