We tested the hypothesis that the pesticides paraoxon and glyphosate cause DNA double-strand breaks (DSB) by poisoning the enzyme Type II topoisomerase (topo II). Peripheral lymphocytes in G0 phase, treated with the pesticides, plus or minus ICRF-187, an inhibitor of Topo II, were stimulated to proliferate; induced cytogenetic damage was measured.

Micronuclei, chromatin buds, nucleoplasmic bridges, and extranuclear fragments were induced by treatments with the pesticides, irrespective of the pre-treatment with ICRF-187. These results indicate that the pesticides do not act as topo II poisons. The induction of DSB may occur by other mechanisms, such as effects on other proteins involved in recombination repair.

我们测试了农药对氧磷和草甘膦通过毒害 II 型拓扑异构酶 (topo II) 导致 DNA 双链断裂 (DSB) 的假设。用农药加或减ICRF-187（Topo II抑制剂）处理G0期外周淋巴细胞，刺激增殖；测量了诱导的细胞遗传学损伤。

无论是否用 ICRF-187 进行预处理，用农药处理都会诱导微核、染色质芽、核质桥和核外片段。这些结果表明该农药不具有拓扑II毒物的作用。DSB 的诱导可能通过其他机制发生，例如对参与重组修复的其他蛋白质的影响。