[Changes in lysosomal enzyme activity in the mitotic cycle of L cells].
Activities of lysosomal enzymes (acid phosphatase, N-acetyl-beta-D-glucosaminidase, acid lipase and cathepsin D) have been examined in a synchronized culture of mouse L-fibroblasts. Cell synchronization was achieved by the double thymidine block with a subsequent mitotic selection after colcemid treatment. Specific activities of the enzymes studied were found to be higher in S-G2 that in G1. There is a linear increase (approximate doubling) in enzyme activities per cell from G1 to M. Activity of galactosyltransferase, a marker of the Golgi apparatus, declined in mitotic cells in comparison with the interphase cells. Ultrastructural examination of L-cells revealed a reduction of the intracellular membrane system including the Golgi apparatus during mitosis. Changes in the Golgi apparatus activity have been considered as a possible regulatory point of lysosome formation. The data presented are compared with the results of morphological studies of lysosomal system in L-cells.
D000818:Animals; D002453:Cell Cycle; D006056:Golgi Apparatus / Q000201:enzymology / Q000648:ultrastructure; D007399:Interphase; D007739:L Cells / Q000201:enzymology* / Q000648:ultrastructure; D008247:Lysosomes / Q000201:enzymology* / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D008938:Mitosis
Izmeneniia aktivnosti lizosomnykh fermentov v mitoticheskom tsikle L-kletok.