Abstract: | An accumulation of lipid material was observed in the alveolar macrophages of animals treated per os with an inhibitor of cholesterol biosynthesis (trans-1, 4-bis) (2-dichlorobenzyl-aminomethyl) cyclohexane dihydrochloride: AY-9944). This lipid is probably 7-dehydro-cholesterol which is a precursor of cholesterol and accumulates in various organs, especially in the lungs. In the rats and pigs the reaction is limited to the alveolar macrophages which are expectorated or degenerate. In dogs some of the alveolar macrophages are also expectorated while others continue to collect a cholesterol-like lipid until large crystals form, which provoke the formation of giant cells and later fibrocytes, giving rise to “cholesterol granulomata”. |