Laboratories of The Rockefeller Institute for Medical Research.
J Exp Med. 1923 Oct 31;38(5):487-97. doi: 10.1084/jem.38.5.487.
When multiplying actively in serum, fibroblasts are in a condition of survival, not of cultivation, for they do not synthetize protoplasm from substances contained in the medium. They are able to utilize only the nitrogenous material stored in the tissue itself. The distinction between survival of tissue and active growth is an important one. Innumerable errors in the interpretation of the experimental results have been made during the past years on account of this lack. An active proliferation of fibroblasts taking place during several days in a medium containing a given substance does not mean that this substance is used by the cells, but indicates only that residual cell proliferation is unopposed by a toxic substance. It is not possible to ascertain whether a medium is nutrient or not in the sense that it supports growth unless the mass of the tissues is shown to increase. When the proliferating fragment can be halved again and again, and each half reaches the size of the original whole in 48 hours, it is evident that new protoplasm must have been synthetized from the medium. The experiments described above show that egg white, egg yolk, pure egg albumin, egg white mixed with egg yolk, and bouillon are not utilized by fibroblasts for multiplication. This fact renders more plausible the hypothesis advanced previously that for proliferation the fibroblasts require some nitrogenous substances elaborated by other cells, which are present in embryonic tissue juices. It may be concluded that, under the conditions of the experiments: 1. The duration of life of pure cultures of fibroblasts in a nitrogen-free medium is about 8 days. 2. Egg white and egg yolk, isolated or together, slightly increase the activity of the fibroblasts, but this effect is temporary and the tissues ultimately die. Pure egg albumin and bouillon are not utilizable by fibroblasts for multiplication.
当成纤维细胞在血清中积极增殖时，它们处于生存状态，而不是培养状态，因为它们不从培养基中的物质中合成细胞质。它们只能利用组织本身储存的含氮物质。组织的生存和活跃生长之间的区别是很重要的。由于这一缺乏，过去几年在解释实验结果时出现了无数错误。在含有给定物质的培养基中活跃增殖数天的成纤维细胞并不意味着该物质被细胞利用，而仅表明细胞增殖不受毒性物质的抑制。除非组织的质量增加，否则无法确定培养基是否具有营养物质，因为它支持生长。当增殖的片段可以一次又一次地减半，并且每个半片在 48 小时内达到原始整个的大小，显然必须已经从培养基中合成了新的细胞质。上述实验表明，蛋清、蛋黄、纯卵白蛋白、蛋清和蛋黄的混合物以及肉汤都不能被成纤维细胞用于增殖。这一事实使得之前提出的假设更加合理，即增殖所需的某些含氮物质是由其他细胞产生的，这些物质存在于胚胎组织液中。可以得出结论，在实验条件下：
无氮培养基中成纤维细胞的纯培养物的寿命约为 8 天。
蛋清和蛋黄，单独或一起，略微增加成纤维细胞的活性，但这种效果是暂时的，组织最终会死亡。纯卵白蛋白和肉汤都不能被成纤维细胞用于增殖。
