Different circadian variations as an indicator of heterogeneity of liver lysosomes

The light and electron microscopic study of the lysosomal marker enzymes acid phosphatase (ACPase), beta-D-glucuronidase and arylsulphatase parallely performed on rat livers obtained during a 24-h span yielded the following results: 1. Lysosomal reactions of these three marker enzymes are subjected to significant circadian variations. 2. The lysosome population visualized by these marker enzymes is obviously heterogeneous. The heterogeneity of the lysosomes is expressed by differences in number, size and lobular distribution as well as in phase differences of their maximal and minimal reactivity depending on the marker enzyme used. 3. With each marker enzyme extralysosomal reactions are found and are also subjected to circadian variations of activity. 4. Applying the arylsulphatase reaction, next to the lysosomes patchy areas of strongly reacting endoplasmic reticulum are found. The arylsulphatase reaction of lysosomes and the endoplasmic reticulum is completely inhibited by 0.01 M KCl.