Studies on the Effects of Steroids on DNA Synthesis of Chromosmoes in Synchronized Human Cells

同時分裂促進된 사람의 培養細胞에 있어서 染色體의 DNA 合成에 미치는 Steroids의 영향

The frequencies of chromosomal aberrations, unmerical variations at various time intervals and DNA synthetic patterns after the treatment with steroids in synchronized human kidney cells treated with 5-AU were investigated in the present experiment. 1. In 5-AU treated group, the frequency of chromosomal aberrations per cell was 0.131, 3 times of control group. In 5-AU + progesterone and 5-AU + testosterone groups, the frequency of chromosomal aberrations per cell was 0.340 and 0.452 respectively. 2. In 5-AU treated group, the frequency of cells with abnormal chromosome number was 0.8%, which was distributed throughout the time regardless of time interval. In 5-AU + progesterone and 5-AU + testosterone groups, the frequencies of cells with abnormal chromosome number were 2.2% and 4.3% respectively and they increased with the time. In 5-AU + progesterone group, the frequency of chromosomal aberrations exhiited the peaks at 12 and 18 hour stage after the treatment with steroids and, in 5-AU + testosterone group, it decreased with the time and in 5-AU treated group no significant difference was observed 3. The increase of labeled metaphases and labelling intensities in 5-AU treated cells are the result of the accumulation of cells at S stage by 5-AU. The decrease of labeled metaphases, labelling intensities and the delay of DNA synthetic time were observed in steroid groups. DNA synthetic pattern of sex chromosomes differs according to the step of cell cycle and DNA synthetic time is irregular because of double treatments with 5-AU and steroids.

5-AU에 의해 同時分裂促進된 사람의 胎兒 賢臟細胞를 材料로 steroid 에 의한 染色體 異常率 時間經過에 따른 染色體異常率, DNA 合成樣相을 調査한 結果는 다음과 같다. 1. 5-AU 處理區에서 細胞當 染色體 異常率은 0.131로 對照區에 比해 3倍 이상이나 된다. 또한 5-AU + progesterone 과 5-AU + testosterone 處理區에서는 細胞當 染色體異常率이 각각 0.340과 0.452이다. 2. 5-AU 處理區에서 異常染色體를 지니는 細胞는 0.8%로 時間變化에 무관하게 전체 其間에 걸쳐 존재한다. 5-AU + progesterone과 5-AU + testosterone 處理區에서는 2.2%, 4.3%의 異常染色體數가 觀察되고, 時間이 지남에 따라 增加한다. 또한 染色體 異常率은 5-AU + progesterone 處理區에서는 12時間과 18時間에 가장 높았고, 5-AU + testosterone 處理區에서는 時間變化에 따라 감소하고 5-AU 處理區에서는 유의한 차이가 없다. 3. 5-AU 는 標識分裂像의 出現頻度와 標識强度를 增加시키는데, 이는 5-AU에 의해 S-stage의 細胞가 축적되는 결과로 생각된다. 그러나 steroid는 標識分裂像의 出現頻度를 감소시키고 DNA 合成時期를 지연시키고 있다. 또한 性染色體의 DNA 合成樣相이 細胞週期의 각 段階에 따라 다르며, 이는 5-AU와 steroid의 二重處理로 DNA 合成時期를 不規則하게 만든 때문이다.