Cell-cycle radiation response: Role of intracellular factors
The quantitative understanding of long-term effects of the components of space radiation on carcinogenesis and nervous-system functions depends on the nature of the molecular injury produced by particles of various atomic numbers and energies. Of particular interest is the functional dependence of individual lesions, their repair and misrepair, and the time-dependent interactions that can occur at low dose rates. Both inherited genetic susceptibility as well as normal programmed genetic functions occurring during cell division could contribute to the vulnerability of cellular targets to damage from ionizing radiations. The authors have studied variations of radiosensitivity and endogenous cellular factors during the course of progression through the human and hamster cell cycle. After exposure to low-LET radiations, the most radiosensitive cell stages are mitosis and the G1/S interface. The increased activity of a specific antioxidant enzyme such as superoxide dismutase in G1-phase, and the variations of endogenous thiols during cell division are thought to be intracellular factors of importance to the radiation-survival response. These factors may contribute to modifying the age-dependent yield of lesions or more likely, to the efficiency of the repair processes. Hazards posed by the interaction of damage from sequential doses of radiations of different qualities have been evaluated and are shown to lead to a cell-cycle-dependent enhancement of radiobiological effects. A summary comparison of various cell-cycle-dependent endpoints measured with low- or high-LET radiations is given and includes a discussion of the possible additional effects introduced by microgravity.
- Research Organization:
- Armed Forces Radiobiology Research Inst., Bethesda, MD (USA)
- OSTI ID:
- 7164944
- Report Number(s):
- AD-A-214331/1/XAB; AFRRI-SR-89-27
- Resource Relation:
- Other Information: Pub. in Adv. Space Res., Vol. 9, No. 10, (10)177-(10)186(1989)
- Country of Publication:
- United States
- Language:
- English
Similar Records
The beneficial health effects of low-level radiation...and why
Radiation and biophysical studies on cells and viruses. Progress report, July 1, 1978-August 30, 1979
Related Subjects
CELL CYCLE
BIOLOGICAL RADIATION EFFECTS
RADIATION QUALITY
RADIOSENSITIVITY
SPACE
IONIZING RADIATIONS
ANTIOXIDANTS
CARCINOGENESIS
CELL DIVISION
DAMAGE
DOSE RATES
ENZYMES
GENETICS
HAMSTERS
HAZARDS
INTERACTIONS
MASS NUMBER
MITOSIS
MOLECULES
NERVOUS SYSTEM
OXIDOREDUCTASES
PARTICLES
PROGRAMMING
RADIATION INJURIES
TIME DEPENDENCE
VULNERABILITY
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGY
INJURIES
MAMMALS
PATHOGENESIS
RADIATION EFFECTS
RADIATIONS
RODENTS
VERTEBRATES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture