Elimination of Chromosome Aberrations from Human Lymphocytes

The frequency of chromosome aberrations in the lymphocytes of 36 hematologically normal women who had received radiation therapy for cervical carcinoma was measured. The decrease with time in the frequency of cells with acentric fragments, of cells with a single dicentric, and of quasidiploid cells can each be represented by a single exponential with an average lifetime, respectively, of 530 ± 64 days, 788 ± 98 days, and 5.55 ± 1.23 x 10³ days. Aneuploid cells fall into two classes: One contains no chromosomes with structural aberrations and shows a stable frequency of about 5.8 per cent; the other contains chromosomes with structural aberrations and is eliminated at the same rate as cells with acentric chromosome fragments. The distribution of dicentrics among the lymphocytes at the end of the radiation therapy period is similar to that shown by a population of lymphocytes exposed in vitro to a single dose of about 300 rads.