[Acid lipases and acid cholesterol esterases: Wolman's disease and cholesteryl ester storage disease].

In the first part of the review are reported the properties of mammalian acid lipases and cholesterol esterases. Lysosomal acid lipase differs from the other acid or neutral lipases by its subcellular localization and a large substrate specificity on natural lipids, triglycerides and cholesteryl esters and on semi-synthetic or synthetic coloured or fluorescent substrates; the enzymatic activity of acid lipase depends on the presence of detergents and phospholipids and the structural properties are well known. In vivo, lysosomal acid lipase hydrolyses neutral lipids from exogenous origin (lipoprotein). The second part is an updated review on the diseases caused by hereditary acid lipase deficiency: Wolman's disease occurring in the first months of life and fatal before the age of one year and Cholesteryl Ester Storage Disease, a more benign form with normal lifespan. Both diseases are characterized by massive storage of neutral lipids. Molecular and metabolic pathways, new diagnostic tools used for the diagnosis and experimental cellular model systems are reviewed and discussed.