title: Individual differences in the radiosensitivity of hematopoietic progenitor cells detected in steady-state human peripheral blood.
abstract: The aim of this study is to evaluate the individual differences in radiosensitivity of lineage-committed myeloid hematopoietic progenitors, colony-forming cells (CFC), detected in steady-state human peripheral blood (PB). Mononuclear cells were prepared from the buffy-coat of 30 individuals PB, and were assayed for CFC by semi-solid culture supplemented with cytokines. X irradiation was performed in the range of 0.5-4 Gy at a dose rate of about 80 cGy/min. The mean number of hematopoietic progenitor cells is 5866 alpha 3408 in 1 ml of buffy-coat, suggesting that the erythroid progenitor cells are the major population. The total CFC radiosensitivity parameter D(0) and n value are 1.18 alpha 0.24 and 1.89 alpha 0.98, respectively. Using a linear regression analysis, a statistically significant correlation is observed between the D(0) value and the surviving fraction at 4 Gy (r = 0.611 p < 0.001). Furthermore, we evaluate the relationship between individual radiosensitivity and the level of antioxidants, plasma uric acid, plasma bilirubin, and intracellular glutathione. No statistically significant correlations are observed, however, between the D(0) parameter and the level of antioxidants, plasma uric acid, plasma bilirubin, and intracellular glutathione. The present study demonstrates that there are large individual differences in the radiosensitivity of hematopoietic progenitor cells as detected in steady-state human PB. These differences demonstrate almost no correlation with plasma or intracellular antioxidants. The prediction of individual differences in radiosensitivity of CFC can only be measured by 4 Gy irradiation.
authors: Department of Radiological Life Sciences, Hirosaki University Graduate School of Health Sciences, Japan.
authors: Asami
authors: A
authors: Oriya
authors: Kenji
authors: K
authors: Takahashi
authors: Osamu
authors: O
authors: Inanami
authors: Toshiaki
authors: T
authors: Miura
authors: Yoshinao
authors: Y
authors: Abe
authors: Mikinori
authors: M
authors: Kuwabara
authors: Ikuo
authors: I
authors: Kashiwakura
mesh_terms: D006412:Hematopoietic Stem Cells / Q000528:radiation effects*; D006801:Humans; D066298:In Vitro Techniques; D011836:Radiation Tolerance; D013234:Stem Cells / Q000528:radiation effects