Pulmonary deposition and clearance of inhaled or instilled 198Au-colloid in the rat after the induction of pulmonary delayed type hypersensitivity reactions.

Abstract

The deposition and clearance of inhaled or instilled colloidal 198Au-particles were studied in rats with pulmonary lesions induced by delayed type hypersensitivity (DTH) reactions. The increased amount of radioactivity was detected in the lung associated lymph nodes and the kidney of DTH rats on day 4 after intratracheal instillation of 198Au-particles. The initial lung deposition of inhaled 198Au-particles in the lung lobes with DTH lesions was approximately 55% of normal lobes. Early mucociliary clearance of 198Au-particles was impaired in DTH rats. These results suggest that the deposition pattern and the subsequent movements of inhaled particles in the respiratory tract might be considerably influenced by pathologic conditions in the lung.