방사선의 반복조사가 랫드 림프구의 염색체이상과 자매염색분체교환에 미치는 영향

The Effects of Fractionated Radiation on Chromosome Aberrations and Sister Chromatid Exchanges in Rat Lymphocyte Culture

This study was undertaken to find out the bio-effects due to be a radiation fractionated exposure. The experimental animals were divided into the control group and the radiation exposure groups of 20cGy, 40cGy and 80cGy with 220 male Sprague-Dawley rats at 6 weeks old. The radiation exposure groups were fractionated exposed from each 20cGy, 40cGy and 80cGy for every 5 days. The chromosome aberrations, the frequency of SCE, the changes of body weight, hematological values and enzyme activities were investigated for the fractionating exposure times and the time after fractionated exposure. The results were summarized as follows 1. The body weight of the radiation exposure groups were significantly decreased compared with control group according to the increasing fractionated exposure times, and it was the lowest values at the immediately after the end of the fractionating exposed, but it was recovered with the level of control group at 3rd weeks gradually increased 1st week after fractionated exposure. 2. The values of WBC, RBC, Hb and Hct in the radiation exposure groups were significantly decreased than those the control group, but the values of GOT, GPT, ALP, and LDH in the radiation exposure groups were significantly increased than those of the control group. 3. The frequency of chromosomal aberration were increased according to the increasing fractionated exposure dose, and it showed the highest at 5th days after fractionated exposed. The types of chromosomal aberration were occurred such as a numerical abnormality, deletion, break and duplication, it was not recovered immediately and maintained high frequency than the control group. 4. The frequency of SCE were significantly increased according to the increasing fractionated exposure dose in 20cGy, 40cGy and 80cGy groups. But it was recovered the level of control group at 7th days after fractionated exposure. According to the above results, this study could confirm that the frequency of chromosomal aberration and SCE were increased with fractionated exposure dose, the other hand, the changes of body weight, hematological values and enzyme activity values were significantly affected according to the increasing fractionated exposure dose.