Abstract
The dynamics of T and B cell immunity in spleens from rat exposed to whole-body chronic irradiation with dose rates of 12·9 cGy/day (range 1–10 Gy) and 3·0 cGy/day (range 0·57–2·04 Gy) were investigated. γ-irradiation with a dose-rate of 12·9 cGy/day was shown to produce a wave-like suppression of the T lymphocyte mitogenic response. Irradiation with a dose-rate of 3·0 cGy/day caused a decrease in immune response of T lymphocytes 48 days after onset of exposure (total dose 1·4 Gy). It was also shown that chronic irradiation with a dose-rate of 3·0 cGy/day produced significant changes in the DNA of T lymphocytes. Our results show that the radiation-induced suppression of immune functions and damage to DNA structure were partially eliminated when animals were fed a daily diet supplemented with a natural antioxidant, ubiquinone Q-9. The inhibiting effect of chronic irradiation was more pronounced in B lymphocytes because of their higher radiosensitivity.