Cytoplasmic Components in Hepatic Cell Lysosomes

De Duve and his colleagues, a few years ago, originated the concept of lysosomes based on the biochemical analysis of isolated cytoplasmic particles (1). He reported that a number of hydrolytic enzymes are concentrated in a fraction consisting of small subcellular units which sediments between the usual mitochondrial and microsomal fractions. Subsequent to this discovery, some of these properties have been demonstrated in hepatic pericanalicular dense bodies, and Essner and Novikoff (2), using the electron microscope, have shown that the enzyme product of acid phosphatase is found exclusively in these bodies. They have also found that a variety of pigment granules in human liver cells possess both