Neurtrophil degranulation in cadmium-chloride-induced acute lung inflammation

Lobar intrabronchial instillation of cadmium chloride (200 micrograms/ml) in saline causes a reproducible acute pulmonary inflammation in dogs. The influx of inflammatory neutrophils from the circulation into the alveolar spaces reaches a maximum approximately 16 hours after the cadmium chloride treatment in the treated lobe, while the controlateral lung appears normal. Morphometric quantitation of peroxidase-positive (azurophilic) granules in the inflammatory neutrophils shows a 74% loss of these granules, with little or no loss of the peroxidase-negative (specific) granules. These data are in good agreement with the measured loss of intracellular elastase, an enzyme known to be localized in the azurophilic granules. The results suggest that degranulation of azurophilic granules may occur selectively during this chemically induced acute inflammation.