Potten C S, Wichmann H E, Loeffler M, Dobek K, Major D
Cell Tissue Kinet. 1982 May;15(3):305-29. doi: 10.1111/j.1365-2184.1982.tb01050.x.
Continuous (repeated) labelling studies in mouse epidermis indicate that nearly all cells are labelled after about 100 hr. Percentage labelled mitoses studies ([3H]TdR at 15.00 and 03.00 hours) have a first peak that does not reach 100% and has a half-width of about 10 hr. Small second and third peaks can be detected at about 90 and 180 hr. respectively. The changes with time in the number of labelled cells show a difference dependent on the time of day of [3H]TdR administration. Both curves show an early doubling in labelled cells which then decline, forming a peak of labelled cells. A second peak occurs at about 120 hr. This is followed by a progressive decline with no further peak until values of about 1% labelling are obtained at 340 hr. These experiments have been investigated mathematically. A computer programme has been devized that permits all three types of experiments to be analyzed simultaneously. More importantly, it can analyse situations with a heterogeneity in cell cycle parameters in all proliferative subpopulations. Various models for epidermal cell replacement have been considered. The data as a whole can best be explained if the basal layer contains at least two distinct subpopulations of cells and an exponentially decaying post-mitotic population with a half-life of about 30 hr. The proliferative sub-populations must be characterized by near integer differences in the length of cycle, the precursor (stem) compartment having the longer cycle. An inverse relationship is required for the length of S, i.e. the shortest time for the stem cells. A full range of cell kinetic parameters can be calculated and are tabulated for the most appropriate model system which is one involving three transit proliferating subpopulations.
对小鼠表皮进行的连续（重复）标记研究表明，约100小时后几乎所有细胞都被标记。标记有丝分裂百分比研究（在15:00和03:00给予[³H]胸腺嘧啶核苷）有一个未达到100%的首个峰值，半峰宽约为10小时。分别在约90小时和180小时可检测到小的第二和第三个峰值。标记细胞数量随时间的变化显示出因给予[³H]胸腺嘧啶核苷的时间不同而存在差异。两条曲线均显示标记细胞早期翻倍，然后下降，形成一个标记细胞峰值。第二个峰值出现在约120小时。随后是逐渐下降，直至340小时获得约1%的标记值时都未出现进一步的峰值。已对这些实验进行了数学研究。设计了一个计算机程序，可同时分析所有三种类型的实验。更重要的是，它可以分析所有增殖亚群中细胞周期参数存在异质性的情况。已经考虑了各种表皮细胞更替模型。如果基底层至少包含两个不同的细胞亚群以及一个半衰期约为30小时的指数衰减的有丝分裂后群体，那么整体数据能得到最好的解释。增殖亚群必须以周期长度的近整数差异为特征，前体（干细胞）区室的周期更长。S期长度需要呈反比关系，即干细胞的最短时间。可以计算出一整套细胞动力学参数，并针对最合适的模型系统制成表格，该模型系统涉及三个过渡增殖亚群。
