Iversen O H, Schjoelberg A R
Virchows Arch B Cell Pathol Incl Mol Pathol. 1984;46(1-2):135-43. doi: 10.1007/BF02890303.
Cell kinetic variables in normal untreated hairless mice were studied in order to observe possible age-related changes. Generally, groups of 4 male and 4 female mice were subjected to study at various ages from one to 115 weeks. The number of basal and suprabasal cells per microscopic field was observed, and after injection of tritiated thymidine the mean labelling index, the average specific activity and the mean grain count were scored. After injection of Colcemid, the average number of Colcemid-arrested mitoses was counted. With flow cytometry the fraction of cells in S and in G2 + M was also observed. In general, both the number of suprabasal cells and the proliferative variables were significantly lower in the very young mice. They increased to slightly above normal values at about 20-22 weeks of age, and then fluctuated a little with two additional possible peaks at 40-50 and around 80 weeks, respectively, and two troughs some weeks after the peaks. However, this rhythmicity was slight and not significant. Thus the only significant age-related pattern was that very young mice have a thin epidermis and low proliferative variables. These values increase up to the age of 20 weeks, and from then on there are no obvious and significant alterations, only slight rhythmic undulations almost within normal limits. The importance of cell kinetic changes with age for epidermal carcinogenesis is discussed in relation to these observations.
为了观察可能的年龄相关变化，对正常未处理的无毛小鼠的细胞动力学变量进行了研究。一般来说，每组4只雄性和4只雌性小鼠在1至115周的不同年龄接受研究。观察每个显微镜视野中基底细胞和基底上层细胞的数量，并在注射氚标记胸腺嘧啶核苷后，对平均标记指数、平均比活性和平均颗粒计数进行评分。注射秋水仙酰胺后，计算秋水仙酰胺阻滞的有丝分裂的平均数量。还用流式细胞术观察了处于S期和G2 + M期的细胞比例。一般来说，非常年幼的小鼠基底上层细胞数量和增殖变量均显著较低。它们在约20 - 22周龄时增加到略高于正常值，然后略有波动，分别在40 - 50周和80周左右出现另外两个可能的峰值，峰值后几周出现两个低谷。然而，这种节律性很轻微且不显著。因此，唯一显著的年龄相关模式是非常年幼的小鼠表皮薄且增殖变量低。这些值在20周龄前增加，从那时起没有明显且显著的变化，只有几乎在正常范围内的轻微节律性波动。结合这些观察结果讨论了细胞动力学随年龄变化对表皮癌发生的重要性。
