Kishimoto T, Fukuzawa Y, Tada M
Department of Environmental Medicine, Shimane Medical University, Izumo, Japan.
Arch Toxicol. 1990;64(5):383-6. doi: 10.1007/BF01973460.
The combined effect of cadmium (CdCl2) and high temperature on the subsequent growth, the synthesis of nucleic acids and protein, and the cell cycle in HeLa S3 cells was investigated. The subsequent growth rate was depressed by cadmium at 37.1 degrees C. This suppression effect was enhanced at 40.4 degrees C compared with the effect at 37.1 degrees C. The synthesis of DNA, RNA and protein was inhibited at higher temperatures in cultivation without cadmium, and depressed at each temperature in a concentration-dependent manner by the addition of cadmium. The DNA, RNA and protein-IC50 values at 40.4 degrees C decreased compared with the values at 37.1 degrees C. The DNA and RNA-IC50 values were significantly decreased (p less than 0.01, p less than 0.005, respectively) depending on the temperature. After treating the cells with cadmium at 40.4 degrees C, the DNA/BrdUrd distribution showed that the rate of dead cells increased and the rate of the G1/G0 phase decreased. These results indicate that the inhibitory effect of cadmium on the subsequent growth of HeLa S3 cells is enhanced at high temperature and this enhancement is related to the increased inhibitory effect of cadmium on DNA and RNA synthesis at high temperature.
研究了镉（CdCl2）与高温对HeLa S3细胞后续生长、核酸和蛋白质合成以及细胞周期的联合作用。在37.1℃时，镉会抑制后续生长速率。与37.1℃时相比，在40.4℃时这种抑制作用增强。在无镉培养条件下，较高温度会抑制DNA、RNA和蛋白质的合成，而添加镉后，在每个温度下其合成均呈浓度依赖性降低。40.4℃时的DNA、RNA和蛋白质半数抑制浓度（IC50）值与37.1℃时相比有所降低。DNA和RNA的IC50值随温度降低显著降低（分别为p<0.01，p<0.005）。在40.4℃用镉处理细胞后，DNA/BrdUrd分布显示死细胞率增加，G1/G0期细胞率降低。这些结果表明，高温会增强镉对HeLa S3细胞后续生长的抑制作用，这种增强与高温下镉对DNA和RNA合成的抑制作用增强有关。
