Saito K
Tohoku J Exp Med. 1986 Mar;148(3):303-12. doi: 10.1620/tjem.148.303.
The effects of paraquat (PQ) on cell growth, DNA, RNA and protein synthesis and on superoxide dismutase (SOD) activity were investigated in cultured pneumocytes of type II cell origin and human embryonic fibroblast cells of the lung. The incorporation of 3H-thymidine, 3H-uridine and 14C-leucine into DNA, RNA and protein, respectively, were all reduced to 25%-70% of the control by PQ at 10(-3) M, but not at 10(-5) M nor 10(-7) M. The activity of SOD in the cells was increased to 130%-270% by 10(-3) M of PQ. Among the cells studied, A-549 cells, which were most resistant to the inhibitory effect of PQ on cell growth and the synthesis of DNA, RNA and protein had the highest induction of SOD activity by PQ. In contrast, L-2 cells in which the cell growth and the synthesis of nucleic acids and protein were most inhibited had the lowest induction of SOD activity by PQ. These results indicate that nucleic acids and protein synthesis are possible targets for lethal effects of PQ in the pulmonary cells, and that the specificity of PQ toxicity in pulmonary cell lines might be related to the ability of induction of SOD by PQ.
研究了百草枯（PQ）对源自II型细胞的培养肺细胞和人胚胎肺成纤维细胞的细胞生长、DNA、RNA和蛋白质合成以及超氧化物歧化酶（SOD）活性的影响。10⁻³ M的PQ可使³H-胸腺嘧啶核苷、³H-尿苷和¹⁴C-亮氨酸分别掺入DNA、RNA和蛋白质的量降至对照的25%-70%，但10⁻⁵ M和10⁻⁷ M的PQ则无此作用。10⁻³ M的PQ可使细胞中的SOD活性增加至130%-270%。在所研究的细胞中，对PQ抑制细胞生长及DNA、RNA和蛋白质合成作用最具抗性的A-549细胞，其SOD活性被PQ诱导的程度最高。相反，细胞生长以及核酸和蛋白质合成受抑制最严重的L-2细胞，其SOD活性被PQ诱导的程度最低。这些结果表明，核酸和蛋白质合成可能是PQ对肺细胞产生致死作用的靶点，并且PQ在肺细胞系中的毒性特异性可能与PQ诱导SOD的能力有关。
