Abstract For decades, theories of cellular radiosensitivity relied upon the initial patterns of energy deposition to explain radiation lethality. Such theories are unsound: cellular (DNA) repair also underlies cellular radiosensitivity. For the charged particles encountered in deep space, both the types of DNA damage caused in cellular deoxyribonucleoproteins the efficacies of their repair are dependent on linear energy transfer (LET∞), and repair efficiency is also influenced by cell and tissue type, i.e., the recovery processes involved. Therefore, quality factors derived from radiation quality alone are inadequate parameters for assessing the radiation risks of space flight. Until recently, OH radicals formed in bulk nuclear water were believed to be the major causes of DNA damage that results in cell death, especially for sparsely ionizing radiations. That hypothesis has now been challenged, if not refuted. Lethal genomic DNA damage is determined mainly by energy deposition in deoxyribonucleoproteins, and their hydration shells, and charge (energy) transfer processes within those structures.
Deoxyribonucleoprotein structure and radiation injury: Cellular radiosensitivity is determined by LET∞-dependent DNA damage in hydrated deoxyribonucleoproteins and the extent of its repair
Advances in Space Research ; 12 , 2-3 ; 51-58
1991-01-01
8 pages
Article (Journal)
Electronic Resource
English
Mechanisms underlying Cellular Radiosensitivity and RBE: Concluding Remarks
Online Contents | 1994
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