Hematopoietic responses under protracted exposures to low daily dose gamma irradiation
| Autor: | D. V. Tolle, T.E. Fritz, Thomas M. Seed, W.E. Jackson |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Atmospheric Science
Neoplasms Radiation-Induced Hematopoietic System Longevity Aerospace Engineering Physiology Radiation Tolerance Risk Assessment Ionizing radiation Dogs Bone Marrow Radioresistance medicine Leukocytes Animals Chronic stress Megakaryopoiesis Leukemia Radiation-Induced business.industry Astronomy and Astrophysics Dose-Response Relationship Radiation Space Flight medicine.disease Hematopoietic Stem Cells Hematopoiesis Leukemia Dose–response relationship Radiation Injuries Experimental Geophysics medicine.anatomical_structure Space and Planetary Science Gamma Rays General Earth and Planetary Sciences Erythropoiesis Bone marrow business Whole-Body Irradiation |
| Zdroj: | Advances in space research : the official journal of the Committee on Space Research (COSPAR). 30(4) |
| ISSN: | 0273-1177 |
| Popis: | In attempting to evaluate the possible health consequences of chronic ionizing radiation exposure during extended space travel (e.g., Mars Mission), ground-based experimental studies of the clinical and pathological responses of canines under low daily doses of 60Co gamma irradiation (0.3-26.3 cGy d-1) have been examined. Specific reference was given to responses of the blood forming system. Results suggest that the daily dose rate of 7.5 cGy d-1 represents a threshold below which the hematopoietic system can retain either partial or full trilineal cell-producing capacity (erythropoiesis, myelopoiesis, and megakaryopoiesis) for extended periods of exposure (>1 yr). Trilineal capacity was fully retained for several years of exposure at the lowest dose-rate tested (0.3 cGy d-1) but was completely lost within several hundred days at the highest dose-rate (26.3 cGy d-1). Retention of hematopoietic capacity under chronic exposure has been demonstrated to be mediated by hematopoietic progenitors with acquired radioresistance and repair functions, altered cytogenetics, and cell-cycle characteristics. Radiological, biological, and temporal parameters responsible for these vital acquisitions by hematopoietic progenitors have been partially characterized. These parameters, along with threshold responses, are described and discussed in relation to potential health risks of the space traveler under chronic stress of low-dose irradiation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect