Alpha Particles Induce Different F Values in Monocellular Layers of Settled and Attached Human Lymphocytes

There is rapidly increasing information on the issue of three-dimensional nuclear architecture, according to which chromosomes are organized in localized territories and chromosome arms in exclusive domains within a given territory. The aim of the present study was to investigate the impact of different cell exposure conditions on cytogenetic damage induced by high-LET radiation. To this end the yield ratio of dicentrics to centric rings (F value) induced by 241Am α particles was analyzed in monolayer cultures of human lymphocytes that were either settled or attached to foils, simulating a rounded or spread out cellular geometry, respectively. Monolayers were exposed in special irradiation chambers to 0.1 and 1.0 Gy and subsequently analyzed for chromosome aberrations. Independent of these different dose levels, significantly different F values of 10.07 ± 1.73 and 4.27 ± 0.44 have been determined in attached and settled lymphocytes, respectively. Since the diameter of nuclei vertically traversed by α part...