[Autoradiographic study of cell kinetics after whole-body x-ray irradiation. II. Study of the patterns of the postradiation death of differentiating and proliferating cells in the subependymal zone of the rat brain].
The post-irradiation cell kinetics was studied in vivo autoradiographically with 3H-thymidine, injected 60-80 minutes before the whole body X-irradiation of rats in doses of 50, 150 or 300 R. The wavy character of death was shown in the proliferating and differentiating rat's brain subependymal cells. After cell irradiation in G2- and S-phases four peaks of labeled mitotic cells with pycnotic nuclei ("mitotic death") were recorded. The application of the double labelling technique with 3H- and 14C-thymidine showed that the lethally damaged cells irradiated in G1-phase had lost their ability to synthesize DNA. The nuclei of these cells became pycnotic later than 4 hours after irradiation, as follows indirectly from data recorded by Shmakova et al. (1972). The conformity in the time and alternation of the death peak appearance of differentiating cells and of the appearance of the death peaks and mitoses in proliferating cells enabled us to assume the persistence of the cycle ("short cycle") in differentiating cells with the rhythm similar to that in the mitotic cycle. All the cells of the system were blocked during one hour, independently of the dose of irradiation, in one of six points of the cycle (mitotic cycle, short cycle). All these data suggest that the death of the differentiating cells and of cells which at the time of irradiation were in G1-phase could be timed to the final phase of the cycle (short cycle, mitotic cycle), coinciding in time with M-phase of the mitotic cycle.
D000818:Animals; D001345:Autoradiography; D002454:Cell Differentiation / Q000528:radiation effects; D002455:Cell Division / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004805:Ependyma / Q000528:radiation effects*; D007399:Interphase / Q000528:radiation effects; D007700:Kinetics; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014916:Whole-Body Irradiation
Avtoradiograficheskoe issledovanie kletochnoĭ kinetiki posle obshchego rentgenovskogo oblucheniia. II. Izuchenie zakonomernosteĭ postradiatsionnoĭ gibeli differentsiruiushchikhsia i proliferiruiushchikh kletok subépendimnoĭ zony golovnogo mozga krys.