Accelerated bone marrow recovery from radiation damage in etoposide-pretreated mice
In: International Journal of Radiation Oncology*Biology*Physics, Jg. 29 (1994-06-01), S. 621-625
Online
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Zugriff:
Purpose: Etoposide inhibits the activity of Topoisomerase II, and possesses radiosensitizing effects on cultured cells. We showed that pretreatment of mice with etoposide 1 day before whole-body irradiation (WBI) had a protective effect against radiation-induced bone marrow death. The number of endogeneous colony-forming units (CFU-S) surviving in WBI mice was significantly increased by pretreatment with etoposide. The purpose of the present study is to clarify mechanisms underlying the protective activity of etoposide against radiation-induced bone marrow damage. Methods and Materials: The spleen colony-forming cells (CFU-S) of femoral marrow were assayed by the method of Till and McCulloch. The proliferative state of CFU-S was assessed using the technique of Hodgson. The reduction in exogeneous CFU-S after hydroxyurea injection was used to determine the fraction size of S-phase in CFU-S. Results: Etoposide pretreatment did not modify the cell survival parameters of exogeneous CFU-S when bone marrow cells were assayed immediately after WBI. Recovery of CFU-S in femoral marrow started earlier in mice receiving etoposide pretreatment than in the radiation alone group. Administration of hydroxyurea revealed that the accelerated recovery of CFU-S was due to an increased population of S phase cells, suggesting etoposide pretreatment shortened generation time of CFU-S. Conclusions: The mechanism for the radioprotection appears to be accelerated proliferation of survived bone marrow cells rather than a change in cellular sensitivity to radiation.
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Accelerated bone marrow recovery from radiation damage in etoposide-pretreated mice
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Autor/in / Beteiligte Person: | Yamada, Shigeru ; Isono, Kaichi ; Koike, Sachiko ; Ando, Koichi |
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Zeitschrift: | International Journal of Radiation Oncology*Biology*Physics, Jg. 29 (1994-06-01), S. 621-625 |
Veröffentlichung: | Elsevier BV, 1994 |
Medientyp: | unknown |
ISSN: | 0360-3016 (print) |
DOI: | 10.1016/0360-3016(94)90469-3 |
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