Effect of low dose rate ionizing radiation on the division potential of cells in vitro. VIII. Cytogenetic analysis of human fibroblasts.

Human embryonic and adult cells were irradiated with fractionated doses of low dose rate ionizing radiation starting early during their lifespan. Adult cells were found to be more sensitive than fetal cells to ionizing radiation in terms of the number of cells produced during the lifespan of the control and the irradiated cultures. Phase-III adult control cells had fewer chromosomal aberrations than phase-III embryonic control cells. After irradiation there was an increase in chromosomal aberrations in adult cells but no increase in embryonic cells beyond those found in the control cultures. It is suggested that cells that have a higher potential for chromosomal rearrangements survive better after low dose rate ionizing radiation.