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Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokinesThe goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p < 0.05). Basal proliferation of leukocytes in the blood and spleen increased significantly with increasing dose (p < 0.05). Significant dose rate effects were observed only in thrombocyte counts. Plasma levels of transforming growth factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.
Document ID
20040112339
Document Type
Reprint (Version printed in journal)
Authors
Gridley, D. S. (Loma Linda University School of Medicine and Medical Center Loma Linda, CA 92354, United States)
Pecaut, M. J.
Miller, G. M.
Moyers, M. F.
Nelson, G. A.
Date Acquired
August 21, 2013
Publication Date
May 1, 2001
Publication Information
Publication: In vivo (Athens, Greece)
Volume: 15
Issue: 3
ISSN: 0258-851X
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Radiation Health
Non-NASA Center