Thorud E, Clausen O P, Bjerknes R, Aarnaes E
Cell Tissue Kinet. 1980 Nov;13(6):625-34. doi: 10.1111/j.1365-2184.1980.tb00501.x.
Groups of hairless mice were injected i.p. with a stathmokinetic dose of 0.15 mg colcemid at seven different times of the day and animals killed 0, 15 and 30 min, 1, 2, 3 and 4 hr after the injection. The proportion of cells in metaphase and ana/telophase was determined in histological sections. The results showed a transient accumulation of metaphases about 30 min after the injection, followed by an increase in metaphases from 1 to 4 hr. Therefore, no value before 1 hr after the colcemid injection should be used in calculations of the mitotic rate. The presence of circadian rhythms with high mitotic activity in the morning and low activity in the evening was confirmed. It is shown by regression analyses that the accumulation period of 4 hr is sufficiently short to reflect circadian variations in epidermal cell proliferation and that the 4-hr accumulation value alone is sufficient to estimate the mitotic rate.
将无毛小鼠分组，在一天中的七个不同时间腹腔注射0.15毫克秋水仙酰胺的有丝分裂抑制剂量，注射后0、15和30分钟、1、2、3和4小时处死动物。在组织学切片中确定处于中期和后期/末期的细胞比例。结果显示，注射后约30分钟中期细胞短暂积累，随后1至4小时中期细胞增加。因此，在计算有丝分裂率时不应使用秋水仙酰胺注射后1小时之前的值。证实了存在昼夜节律，即早晨有丝分裂活性高，晚上活性低。回归分析表明，4小时的积累期足够短，足以反映表皮细胞增殖的昼夜变化，仅4小时的积累值就足以估计有丝分裂率。
