Chromosomal Aberrations in Human Lymphocytes Irradiated in Vitro from Donors (Males and Females) of Varying Age

Summary

PHA-stimulated peripheral blood lymphocytes of 43 donors, females and males of the age 0 (newborn) to 72 years, were irradiated in vitro with a constant dose of x-rays (300 rads) at 37°c. The cells were studied in the metaphase of the first mitosis and scored for the presence of chromosomal aberrations. No difference in the yield of the latter in lymphocytes from males and females could be detected. Whereas the frequency of acentric fragments, rings and intercalary deletions was independent of the donors' ages, the yield of dicentrics was linearly and negatively correlated with this parameter. The average decrease of the dicentric yield with age amounted to 0·4 per cent per year, when related to the frequency per cell in the newborn.

After a constant x-ray dose, no individual variation was observed in the yield of rings, intercalary deletions and dicentrics, if the age effect for the last aberration type was corrected for. The yield of acentric fragments displayed a significant donor-to-donor variation.