We studied daily dynamics of proliferative activity of embryonic fibroblast-like cells in culture during the logarithmic growth phase. Daily increase in cell count in the culture showed a 4-day rhythm that persisted over 3 weeks of culturing. In cultures from different animals, the phase of this rhythm was synchronous and did not depend on the moment of cell isolation. It can be hypothesized that the 4-day biorhythm of proliferative activity of embryonic fibroblast-like cells in culture is determined by external environmental factors, probably of electromagnetic nature.

中文翻译：

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来自 C57BL/6 小鼠的胚胎成纤维细胞样细胞培养物增殖活性的 Infradian 节律

我们研究了对数生长期期间培养的胚胎成纤维细胞样细胞增殖活性的日常动态。培养物中细胞计数的每日增加显示出持续 3 周培养的 4 天节律。在来自不同动物的培养物中，这种节奏的阶段是同步的，不依赖于细胞分离的时刻。可以假设培养中胚胎成纤维细胞样细胞增殖活动的 4 天生物节律是由外部环境因素决定的，可能是电磁性质的。