DNA 回復合成과 染色體交換과의 聯關性을 추구하기 위해 감마線을 照射한 BHK-21 과KB 細胞의 DNA 回復合成의 線量反應과 時期를 調査하였다. 감마 線에 의한 DNA 回復合成率은 5kR까지 照射線量에 比例하나 그후 50kR 까지는 變化가 없었다. DNA 回復合成의 初期 線量反應은 細胞에 따라 다르나 照射후 1$\sim$2時間까지 지속하였다. 감마 線에 의한 染色體交換은 細胞에 따라 다른 感受性을 보였고 DNA 回復合成과의 聯關性을 보여주지 않았다.
Dose response and time dependence of DNA repair synthesis were investigated to determine the possible relationship between DNA repair synthesis and chromosome exchanges in $\gamma$-ray irradiated BHK-21 and KB cell lines. DNA repair synthesis induced by $\gamma$-ray was dose dependent up to 5kR, then leveling off occurred until 50 kR was reached. Time dependence of DNA repair synthesis was continued for up to 1$\sim$2 hours after irradiation although the initial dose responses were cell line specific. Chromosome exchanges induced by $\gamma$-ray showed different radiosensitivities in these cell lines and did not show a correlation with the DNA repair synthesis.
