Necas E, Neuwirt J
Cell Tissue Kinet. 1976 May;9(3):257-66. doi: 10.1111/j.1365-2184.1976.tb01273.x.
The response of polycythaemic mice to a standard dose of erythropoietin has been measured at various time intervals after single or repeated injections of hydroxyurea. The results exclude S phase of the cell cycle as the period responsive to erythropoietin. They suggest the existence of feedback mechanisms within the cell cycle, operating at the G1--S boundary and within the G1 phase. Hydroxyurea given to polycythaemic mice at various time intervals after erythropoietin induced characteristic changes in the response. These changes can be explained if both gradual transit of differentiated cells into the DNA synthesis (S phase) and changes in amount of the erythropoietin sensitive cells caused by the feedback mechanisms operating in the cell cycle are considered.
在单次或重复注射羟基脲后的不同时间间隔，测定了红细胞增多症小鼠对标准剂量促红细胞生成素的反应。结果排除了细胞周期的S期是对促红细胞生成素产生反应的时期。这些结果提示在细胞周期内存在反馈机制，该机制在G1-S边界及G1期起作用。在促红细胞生成素给药后的不同时间间隔给红细胞增多症小鼠注射羟基脲，可诱导反应发生特征性变化。如果考虑到分化细胞逐渐进入DNA合成期（S期）以及细胞周期中反馈机制引起的促红细胞生成素敏感细胞数量变化，那么这些变化就可以得到解释。
