Tanaka R, Amano Y
J Toxicol Sci. 1985 Nov;10(4):309-14. doi: 10.2131/jts.10.309.
Paraquat, a popular herbicide, is known to be very toxic to man and animals. Using cultured mammalian cells (human embryo lung cell, R-66), the effect of paraquat has been studied. With autoradiography, stimulation of DNA synthesis was observed when the cells were exposed to 0.08 or 0.4 microM of paraquat; however, DNA synthesis was inhibited with 40 microM of paraquat. To determine cell growth rate, accumulation of mitotic cells was determined after addition of colcemid (0.2 microgram/ml) into the culture medium. The ratios of mitotic cells observed were proportional to the level of DNA synthesis. And the stimulation and inhibition of cell growth were observed even after washing off paraquat from media.
百草枯是一种常见的除草剂，已知对人和动物具有剧毒。利用培养的哺乳动物细胞（人胚肺细胞，R - 66），对百草枯的作用进行了研究。通过放射自显影法，当细胞暴露于0.08或0.4微摩尔的百草枯时，观察到DNA合成受到刺激；然而，当百草枯浓度为40微摩尔时，DNA合成受到抑制。为了确定细胞生长速率，在向培养基中添加秋水仙酰胺（0.2微克/毫升）后，测定有丝分裂细胞的积累情况。观察到的有丝分裂细胞比例与DNA合成水平成正比。即使从培养基中洗去百草枯后，仍观察到细胞生长的刺激和抑制现象。
