Relative implications of protective responses versus damage induction at low dose and low-dose-rate exposures, using the microdose approach
Autor: | Feinendegen Le |
---|---|
Rok vydání: | 2003 |
Předmět: |
DNA damage
DNA repair Linear energy transfer Apoptosis Endogeny Pharmacology Radiation Dosage Models Biological Radiation Tolerance Risk Assessment Cell Physiological Phenomena Toxicology MicroDose medicine Animals Humans Linear Energy Transfer Radiology Nuclear Medicine and imaging Irradiation Radiometry Cell damage Radiation Radiological and Ultrasound Technology Chemistry Public Health Environmental and Occupational Health Dose-Response Relationship Radiation DNA General Medicine medicine.disease Adaptation Physiological Absorbed dose DNA Damage |
Zdroj: | Radiation Protection Dosimetry. 104:337-346 |
ISSN: | 1742-3406 0144-8420 |
DOI: | 10.1093/oxfordjournals.rpd.a006197 |
Popis: | In reviewing the tissue effects of low-dose radiation (1) absorbed dose to tissue is replaced by the sum of energy deposited with track events in cell-equivalent tissue micromasses, i.e. with microdose hits, in the number of exposed micromasses and (2) induced cell damage and adaptive protection are related to microdose hits in exposed micromasses for a given radiation quality. DNA damage increases with the number of microdose hits. They also can induce adaptive protection, mainly against endogenous DNA damage. This protection involves cellular defences, DNA repair and damage removal. With increasing numbers of low linear energy transfer (LET) microdose hits in exposed micromasses, adaptive protection first tends to outweigh damage and then (above 200 mGy) fails and largely disappears. These experimental data predict that cancer risk coefficients derived by epidemiology at high-dose irradiation decline at low doses and dose rates when adaptive protection outdoes DNA damage. The dose-risk function should include both linear and non-linear terms at low doses. |
Databáze: | OpenAIRE |
Externí odkaz: |