Morris G M, van den Aardweg G J, Hamlet R, Whitehouse E, Hopewell J W, Franke H, Loeffler M
CRC Normal Tissue Radiobiology Research Group, Research Institute (University of Oxford), Churchill Hospital, U.K.
Cell Tissue Kinet. 1990 Mar;23(2):113-23. doi: 10.1111/j.1365-2184.1990.tb01338.x.
The durations of the cell cycle and its component phases have been determined for the basal layer of the epidermis of the skin from the upper surface of the hind foot of the rat using single pulse [3H]-thymidine labelling and the percent labelled mitosis (PLM) technique. Rats of three age groups were used, namely 7, 14 and 52 weeks. The duration of DNA synthesis (Ts) and the G2 plus M phase (TG2 + M) were comparable in 7-week and 52-week-old rats (P greater than 0.1). The major difference between 7-week and 52-week-old rats was in the duration of the G1 phase (TG1). In 7-week-old rats TG1 was 15.0 +/- 0.8 h and in 52-week-old rats TG1 was 31.2 +/- 3.5 h. A consequence of this variation was that the overall duration of the cell cycle was longer in 52-week-old rats (53.9 +/- 5.3 h) than in 7-week-old rats (30.1 +/- 1.3 h). Difficulties were found in fitting a simple curve to the PLM data for 14-week-old rats. This suggests that the proliferative cell population of the epidermis of rats of this age group may be heterogeneous. A satisfactory fit to the data was obtained using a computer model which assumed that the proliferative population of the epidermis of 14-week-old rats was a mixture of cells with cell cycle parameters the same as those of the 7-week and the 52-week-old rats. These two sub-populations of relatively slowly and rapidly proliferating cells were present in the ratio of 2:1.
使用单脉冲[3H]-胸腺嘧啶核苷标记法和标记有丝分裂百分数（PLM）技术，已测定了大鼠后足上表面皮肤表皮基底层细胞周期及其各组成阶段的持续时间。使用了三个年龄组的大鼠，即7周、14周和52周龄。7周龄和52周龄大鼠的DNA合成期（Ts）以及G2加M期（TG2 + M）的持续时间相当（P大于0.1）。7周龄和52周龄大鼠之间的主要差异在于G1期（TG1）的持续时间。7周龄大鼠的TG1为15.0±0.8小时，52周龄大鼠的TG1为31.2±3.5小时。这种差异的一个结果是，52周龄大鼠的细胞周期总持续时间（53.9±5.3小时）比7周龄大鼠（30.1±1.3小时）更长。发现难以用简单曲线拟合14周龄大鼠的PLM数据。这表明该年龄组大鼠表皮的增殖细胞群体可能是异质性的。使用计算机模型获得了对数据的满意拟合，该模型假设14周龄大鼠表皮的增殖群体是细胞周期参数与7周龄和52周龄大鼠相同的细胞混合物。这两个增殖相对缓慢和快速的细胞亚群的比例为2:1。
