Effects of Emphysema on Deposition and Clearance of Inhaled Particles

Abstract

Centrilobular emphysemas were induced in mice (ICR/Jcl, female) by inhalation of papain (a proteolytic enzyme contained in Papaya fruit) aerosol. Then, these mice were exposed to Cr₂O₃ dust (4.45±0.27 mg/m³, 2.4±1.7 μm) for 5 hrs. Average amount of deposited dust in the lungs of emphysema-induced mice was about 70% of that of control animals, immediately after the exposure. Whereas the clearance of dust was reduced in emphysema-induced mice, amount of residual dust in the lungs of emphysema-induced mice were higher than that of control at 6 months after the dust exposure.