Age-related changes in radiation-induced micronuclei among healthy adults

Abstract

The aim of the present study was to establish the extent of in vitro radioresponse of lymphocytes among 62 healthy adults of both genders and to estimate the distribution of baseline micronuclei and radiosensitivity among individuals of the study population using the cytochalasin block micronucleus test. A younger study group consisted of 10 males (mean age, 22.4 years; range, 21-27) and 12 females (mean age, 24.8 years; range, 20-29), whereas an older study group consisted of 18 males (mean age, 35.1 years; range, 30-44) and 22 females (mean age, 38.5 years; range, 30-48). For evaluation of radiosensitivity blood samples were irradiated in vitro using 60 Co γ-ray source. The radiation dose employed was 2 Gy, the dose rate 0.45 Gy/ min. The study revealed a significant gender effect on baseline micronuclei favoring females (Z = 3.25, P < 0.001), while yields of radiation-induced micronuclei did not differ significantly (Z = 0.56, P < 0.56) between genders. The distribution of baseline micronuclei among the individuals tested followed Poisson distribution in both study groups and in both genders, whereas the distribution of radiosensitivity among individuals of the older study group did not fulfill Poisson expectations (Kolmogorov-Smirnof test, P < 0.01). In contrast to a nonsignificant difference in radiosensitivity between males and females of the same age group (Z = 1.97, P < 0.56), a statistically significant difference in radiosensitivity between younger and older group for both genders was found (Z = 3.03, P < 0.03). Since the individuals tested were healthy, the observed variability in radiation response is considered to be an early effect of ageing.

Dynamics of Micronuclei in Rat Skin Fibroblasts after X Irradiation

“…3A), there is generally good agreement between the two experiments, and it is seen that the number of micronuclei per 1000 binucleate cells remained essentially unchanged up to 60-70 days postirradiation and then began to decrease by about day 100 but remained well above background at more than a year after irradiation. In this context, it is of interest that background micronuclei were generally found to be independent of the age of the animal, which is in accordance with a previous study using activated lymphocytes (17). For the animals treated with 18 Gy (Fig.…”

Biogerontology in Serbia

“…Furthermore, the plasma levels of antioxidants could be an important indicators for breast cancer radiotherapy protocol decisions. Another study suggested (Joksić et al 2004) that the variability of radiation response of lymphocytes in vitro and the distribution of baseline micronuclei could be one of early effect of aging.…”