Jagetia G C, Aruna R
Department of Radiobiology, Kasturba Medical College, Manipal, India.
Toxicol Lett. 1999 Feb 22;104(3):203-10. doi: 10.1016/s0378-4274(98)00368-3.
The effect of various doses (0-10 mg/kg body wt.) of teniposide (VM-26) was studied on the induction of micronuclei at 12, 24 and 36 h post-treatment. The frequency of micronuclei (MPCE and MNCE) increased in a dose-dependent manner up to a dose of 0.3125 mg/kg VM-26, where a peak frequency of micronuclei was observed. A further increase in the drug dose resulted in the reduction in micronuclei frequency in comparison with 0.3125 mg/kg drug dose reaching a nadir at 10 mg/kg. However, it was significantly higher than DDW (double distilled water) treated controls. The pattern of micronuclei induction was similar for all the post-treatment time periods. The frequency of micronuclei also increased with scoring time and the highest frequency of micronuclei was observed at 24 h post-treatment, which declined thereafter without restoration to DDW treated control level. Conversely, the PCE/NCE ratio registered a dose-dependent decline after treatment of mice with various doses of VM-26. A peak decline was observed at a dose of 0.3125 mg/kg, thereafter the decline became consistently less resulting in an elevation in the PCE/NCE ratio in comparison with 0.3125 mg/kg VM-26.
研究了不同剂量（0 - 10毫克/千克体重）的替尼泊苷（VM - 26）在处理后12、24和36小时对微核诱导的影响。微核频率（MPCE和MNCE）以剂量依赖性方式增加，直至0.3125毫克/千克VM - 26剂量时观察到微核频率峰值。与0.3125毫克/千克药物剂量相比，药物剂量进一步增加导致微核频率降低，在10毫克/千克时达到最低点。然而，它显著高于双蒸水（DDW）处理的对照组。所有处理后时间段的微核诱导模式相似。微核频率也随着计分时间增加，在处理后24小时观察到最高微核频率，此后下降且未恢复到DDW处理的对照组水平。相反，用不同剂量的VM - 26处理小鼠后，PCE/NCE比值呈剂量依赖性下降。在0.3125毫克/千克剂量时观察到峰值下降，此后下降持续减少，与0.3125毫克/千克VM - 26相比，PCE/NCE比值升高。
