The aim of the present in vivo study was to determine the kinetics of the genotoxic and cytotoxic activities of cladribine and clofarabine in mouse normoblasts using flow cytometry. Mice in groups of five were treated with cladribine or clofarabine. Blood samples were obtained from the mouse tails before treatment and every 8 hr posttreatment for 72 hr. These samples were cytometrically scored for micronucleated reticulocytes (RETs), and the percentage of RETs was determined. The results showed that clofarabine and cladribine have early cytotoxic effects that are related to the genotoxic effects reported in previous studies; the drugs have both complex long‐lasting genotoxic and cytotoxic kinetic activity, with similar profiles that suggest a relationship between the genotoxic and cytotoxic parameters. The initial genotoxkinetics timing of clofarabine is equivalent to those of difluorodeoxycytidine, likely because both agents inhibit DNA polymerase. Clofarabine shows a higher genotoxic and cytotoxic efficiency than cladribine, in agreement with previous results.

中文翻译：

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克拉屈滨和氯法拉滨的遗传毒性和细胞毒性活性的体内动力学。

本体内研究的目的是使用流式细胞术确定克拉屈滨和氯法拉滨在小鼠成胚细胞中的遗传毒性和细胞毒性活性的动力学。五只一组的小鼠接受克拉屈滨或氯法拉滨治疗。在治疗前和治疗后每8小时72小时从小鼠尾部采集血样。用细胞计数法对这些样品的微核网织红细胞（RET）进行评分，并确定RET的百分比。结果表明，氯法拉滨和克拉屈滨具有早期细胞毒性作用，与先前研究报道的遗传毒性作用有关。这些药物具有复杂的持久遗传毒性和细胞毒性动力学活性，具有相似的特征，表明遗传毒性和细胞毒性参数之间存在关联。氯法拉滨的初始遗传代谢动力学时机与二氟脱氧胞苷相同，可能是因为两种试剂均抑制DNA聚合酶。氯法拉滨与克拉屈滨相比，具有更高的遗传毒性和细胞毒性功效，与以前的结果一致。