Scanning and transmission electron microscopy following irradiation of Ehrlich ascites tumour cells. Relationships to cell cycle.
Following irradiation with 5 Gy, Ehrlich ascites tumour cells growing in vivo were separated by means of elutriator centrifugation into G1, S-phase and G2 + M cells. The surface and internal morphology of the cells was analysed using scanning and transmission electron microscopy and compared with non-irradiated controls. Marked changes of the cell surface were found 5 to 72 h after irradiation, with the development of long straight microvilli mainly in S-phase and G2 cells and the appearance of cells without microvilli in G1. The latter were generally associated with intracellular degenerative changes. The appearance of these microvilli, and the consequent increase in cellular surface area was correlated to enlargement of the Golgi complex. Changes in the distribution of intracellular organelles were noted 5 h after irradiation in cells from all stages of the cell cycle. An increase of the ratio of polyribosomes to ribosomes was found in S-phase and G2 cells up to 72 h. The appearance of long microvilli was not related to a redistribution of cells in cell cycle and occurred below doses at which changes in cell membrane function are usually found.
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000473:pathology / Q000532:radiotherapy* / Q000648:ultrastructure; D002453:Cell Cycle; D005260:Female; D051379:Mice; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009368:Neoplasm Transplantation