caa a22 4500 445813032 CHVBK 20180317145217.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s00411-011-0382-9 doi (NATIONALLICENCE)springer-10.1007/s00411-011-0382-9 Mutation induction by inhaled radon progeny modeled at the tissue level [Elektronische Daten] [Balázs Madas, Imre Balásházy] The observable responses of living systems to ionizing radiation depend on the level of biological organization studied. Understanding the relationships between the responses characteristic of the different levels of organization is of crucial importance. The main objective of the present study is to investigate how some cellular effects of radiation manifest at the tissue level by modeling mutation induction due to chronic exposure to inhaled radon progeny. For this purpose, a mathematical model of the bronchial epithelium was elaborated to quantify cell nucleus hits and cell doses. Mutagenesis was modeled considering endogenous as well as radiation-induced DNA damages and cell cycle shortening due to cell inactivation. The model parameters describing the cellular effects of radiation are obtained from experimental data. Cell nucleus hits, cell doses, and mutation induction were computed for the activity hot spots of the large bronchi at different exposures. Results demonstrate that the mutagenic effect of densely ionizing radiation is dominated by cell cycle shortening due to cell inactivation and not by DNA damages. This suggests that radiation burdens of non-progenitor cells play a significant role in mutagenesis in case of protracted exposures to densely ionizing radiation. Mutation rate as a function of dose rate exhibits a convex shape below a threshold. This threshold indicates the exhaustion of the tissue regeneration capacity of local progenitor cells. It is suggested that progenitor cell hyperplasia occurs beyond the threshold dose rate, giving a possible explanation of the inverse dose-rate effect observed in the epidemiology of lung cancer among uranium miners. Springer-Verlag, 2011 Madas Balázs Hungarian Academy of Sciences KFKI Atomic Energy Research Institute, Budapest, Hungary aut Balásházy Imre Hungarian Academy of Sciences KFKI Atomic Energy Research Institute, Budapest, Hungary aut Radiation and Environmental Biophysics Springer-Verlag 50/4(2011-11-01), 553-570 0301-634X 50:4<553 2011 50 411 https://doi.org/10.1007/s00411-011-0382-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00411-011-0382-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Madas Balázs Hungarian Academy of Sciences KFKI Atomic Energy Research Institute, Budapest, Hungary aut NATIONALLICENCE 700 1- Balásházy Imre Hungarian Academy of Sciences KFKI Atomic Energy Research Institute, Budapest, Hungary aut NATIONALLICENCE 773 0- Radiation and Environmental Biophysics Springer-Verlag 50/4(2011-11-01), 553-570 0301-634X 50:4<553 2011 50 411 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer