KINETICS OF CELL RENEWAL CELL MIGRATION AND CELL LOSS IN THE HAIRLESS MOUSE DORSAL EPIDERMIS
KINETICS OF CELL RENEWAL CELL MIGRATION AND CELL LOSS IN THE HAIRLESS MOUSE DORSAL EPIDERMIS
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DOI：
10.1111/j.1365-2184.1968.tb00964.x
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发表时间：
1968-01-01
期刊：
影响因子：
--
通讯作者：
DEVIK F
中科院分区：
文献类型：
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作者：
IVERSEN O H;BJERKNES R;DEVIK F
40只无毛小鼠在10天内每隔4小时注射一次氚化胸苷。每隔24小时处死一组四只小鼠。标记的基底细胞和分化细胞的数量通过放射自显影与剥离膜技术来确定。为了确定背景放射性，对未注射的对照小鼠的皮肤切片进行同样的剥膜处理，对另一组无毛小鼠进行一次氚标记胸苷脉冲标记。注射后12小时对标记的有丝分裂数进行评分。在注射后10、12和15小时，测定了标记的基底细胞和分化细胞的数量，提出了表皮细胞群体动力学的数学模型。对该模型进行不同模拟的结果与观测结果进行了比较，连续标记下的平均颗粒数曲线逐日增加，有两个明显的平台，到第3天标记细胞百分比迅速增加，此后曲线逐渐变平。将基底细胞和分化细胞分开考虑，基底细胞的标记指数在前3天迅速增加，第5天趋于平稳，在100%水平，分化细胞的标记指数在前3-4天较低。然后，观察到标记的分化细胞的百分比急剧增加，但曲线在第7天后再次变平，接近100%水平。标记的有丝分裂曲线在注射胸苷后5小时达到最大值。注射后10、12和15小时，棘层中分别有6%、7%和7%的标记细胞，因此，以每个核上有3个颗粒为标记细胞的下限。在此基础上，每4小时注射一次氚化胸苷可视为连续标记。
Forty hairless mice were given injections of tritiated thymidine every 4th hour during 10 days. At 24 hr intervals groups of four mice were killed. The numbers of labelled basal and differentiating cells were determined by autoradiography with a stripping film technique. To determine the background activity skin sections from uninjected control mice were subjected to the same stripping film procedure.Another group of hairless mice was given one single pulse labelling with tritiated thymidine. The number of labelled mitoses was scored for 12 hr after the injection. At 10, 12 and 15 hr after the injection, the numbers of labelled basal and differentiating cells were also determined.A mathematical model of cell population kinetics in the epidermis has been suggested. The results of different simulations on this model were compared with the observed results.The curve of mean grain counts under continuous labelling increased from day to day with two well‐defined plateaux.The percentage of all labelled cells increased rapidly up to the 3rd day, and thereafter the curves gradually flattened off. When basal cells and differentiated cells were considered separately the labelling index of the basal cells increased rapidly for the first 3 days and then flattened off at the 100% level on the 5th day.The labelling index of the differentiating cells was low during the first 3–4 days. Then a steep increase in the percentage of labelled differentiating cells was seen, but the curve flattened off again close to the 100 % level after the 7th day. The labelled mitosis curve had its maximum 5 hr after the thymidine injection. The curve fell again to almost zero at 12 hr. Ten, 12 and 15 hr after the injection, 6, 7 and 7% respectively of the labelled cells were found in the spinous layer.It was concluded that three grains over each nucleus could be used as lower limit for considering a cell as labelled. On this basis, tritiated thymidine injections every 4th hour can be considered as continuous labelling.