Abstract
Six particulate preparations isolated from rat liver under different experimental conditions were analyzed biochemically and examined in the electron microscope. The results confirm the lysosomal nature of the pericanalicular dense bodies and demonstrate that the microbodies are the bearers of urate oxidase, catalase, and D-amino acid oxidase. Catalase, representing a major component of the particles, and D-amino acid oxidase appear to be associated with the structureless "sap" of the particles, urate oxidase with their crystalloid core or with their outer membrane.