Miadelets O D
Ontogenez. 1995 Jan-Feb;26(1):62-7.
Quantitative ratios between reproduction of the keratinocytes and their apoptotic death vary in different periods of postnatal ontogenesis. During the first month of life of the rats the mitotic activity of keratinocytes and thickness of the epidermis gradually decrease. The epidermis undergoes further development, which terminates by the 30th day after birth. The number of apoptotic cells in the epidermis increases from the 1st until 16th day and that of intraepidermal lymphocytes from the 1st until 30th day. In 3-month old animals the peak of mitotic activity coincided with the enhanced apoptotic death of the keratinocytes. The anagen signs were noted in such animals. In the old rats the mitotic activity of the epidermal cells was markedly reduced with the increased rate of apoptosis of the keratinocytes and the decreased thickness of epidermis. Single Merkel cells were visualized in the epidermis using the silver plating technique. Hence, their role in apoptosis of the keratinocytes cannot be significant. The possibility of lymphocyte-associated apoptosis of the keratinocytes in the early postnatal ontogenesis of rats is assumed.
角质形成细胞的增殖与其凋亡死亡之间的定量比率在出生后个体发育的不同时期有所不同。在大鼠出生后的第一个月，角质形成细胞的有丝分裂活性和表皮厚度逐渐降低。表皮会经历进一步发育，在出生后第30天结束。表皮中凋亡细胞的数量从第1天到第16天增加，表皮内淋巴细胞的数量从第1天到第30天增加。在3个月大的动物中，有丝分裂活性的峰值与角质形成细胞凋亡死亡的增加相吻合。在这些动物中观察到了生长期的迹象。在老年大鼠中，表皮细胞的有丝分裂活性明显降低，角质形成细胞的凋亡率增加，表皮厚度减小。使用镀银技术在表皮中观察到单个默克尔细胞。因此，它们在角质形成细胞凋亡中的作用可能并不显著。推测在大鼠出生后早期个体发育过程中存在淋巴细胞相关的角质形成细胞凋亡的可能性。
