Biological Effects of High-Energy Neutrons MeasuredIn VivoUsing a Vertebrate Model
| Autor: | William S. Dynan, Wendy W. Kuhne, Varghese George, Honglu Wu, Richard Wilkins, Brad Gersey, Stephen A. Wender |
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| Rok vydání: | 2009 |
| Předmět: |
High energy
Embryo Nonmammalian Endpoint Determination Quantitative Biology::Tissues and Organs Oryzias Biophysics Apoptosis Cosmic ray Biology Article In vivo Animals Radiology Nuclear Medicine and imaging Neutron Spallation Neutrons Radiation Equivalent dose business.industry Muscles Radiochemistry Dose-Response Relationship Radiation Neutron radiation biology.organism_classification Survival Analysis Models Animal Tumor Suppressor Protein p53 Nuclear medicine business Biomarkers DNA Damage |
| Zdroj: | Radiation Research. 172:473-480 |
| ISSN: | 1938-5404 0033-7587 |
| Popis: | Interaction of solar protons and galactic cosmic radiation with the atmosphere and other materials produces high-energy secondary neutrons from below 1 to 1000 MeV and higher. Although secondary neutrons may provide an appreciable component of the radiation dose equivalent received by space and high-altitude air travelers, the biological effects remain poorly defined, particularly in vivo in intact organisms. Here we describe the acute response of Japanese medaka (Oryzias latipes) embryos to a beam of high-energy spallation neutrons that mimics the energy spectrum of secondary neutrons encountered aboard spacecraft and high-altitude aircraft. To determine RBE, embryos were exposed to 0-0.5 Gy of high-energy neutron radiation or 0-15 Gy of reference gamma radiation. The radiation response was measured by imaging apoptotic cells in situ in defined volumes of the embryo, an assay that provides a quantifiable, linear dose response. The slope of the dose response in the developing head, relative to reference gamma radiation, indicates an RBE of 24.9 (95% CI 13.6-40.7). A higher RBE of 48.1 (95% CI 30.0-66.4) was obtained based on overall survival. A separate analysis of apoptosis in muscle showed an overall nonlinear response, with the greatest effects at doses of less than 0.3 Gy. Results of this experiment indicate that medaka are a useful model for investigating biological damage associated with high-energy neutron exposure. |
| Databáze: | OpenAIRE |
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