Experimental silicosis: the inhibitory effect of iron.

In 1932 Kettle1 reported that where quartz particles are coated with iron their fibrogenic action is inhibited. Although initially unsuccessful, Gardner was able to confirm this inhibitory action in 1938. More recently Vorwald4 also described the inhibitory action of iron on experimental silicosis in guinea pigs. Finely divided metallic aluminum powder according to Denny et al.,#{176} and aluminum hydroxide according to Gardner1 also inhibit experimental silicosis. Gardner2 concluded that no inhibition could occur unless the inhibiting substance was within the same macrophage as the quartz particle it inhibited. It is the purpose of this paper to describe the topographic relationship of the iron and silica in the lungs of rats and guinea pigs in which experimental silicosis had been inhibited by iron, and to discuss certain findings which appear to be at variance with the above-mentioned conclusion of Gardner2 concerning this inhibition. Method