An analysis of alveolar macrophage mobility kinetics at dust overloading of the lungs

On the basis of a compartmental model, an analysis is presented to describe the alveolar clearance of insoluble particles from the rat lungs at excessive lung burdens. Expressions for the transport rate of the model are derived in terms of the alveolar macrophage mobility kinetics. It is shown that the reduction of alveolar clearance from the lungs at excessive burdens is caused by a reduction of macrophage mobility at high particle burdens and increasing number of deposited particles entering the interstitial space. On the basis of these hypotheses, and the results of other studies, calculations show that a macrophage maintains its mobility up to a certain particle burden and beyond this burden the mobility is dramatically reduced.