Baribault H, Leroux-Nicollet I, Marceau N
J Cell Physiol. 1985 Jan;122(1):105-12. doi: 10.1002/jcp.1041220116.
The capacity of suckling and adult rat hepatocytes in culture to enter into S phase and mitosis in response to EGF, insulin, and glucagon was measured. Both cell types were isolated in high yield and purity and cultured in the absence of serum under identical conditions. At the time of isolation, suckling rat hepatocytes were all diploid and in the G1 phase of the cell cycle. Adult rat hepatocytes constituted a population of mixed ploidy level, as shown by flow cytometry. Upon stimulation, both suckling and adult rate hepatocytes entered S phase after a minimum lag period of 24 h. For suckling rat hepatocytes EGF was required, but its stimulating action was dependent on insulin and/or glucagon. In contrast, adult rat hepatocytes entered into S phase in response to EGF alone; insulin and glucagon did not significantly potentiate its effect. Under optimal hormonal stimulation for entry into S phase a large proportion of suckling rat hepatocytes underwent mitosis, whereas only a few mitoses were observed in the case of adult rat hepatocytes. Therefore, there is a differential response of suckling and adult rat hepatocytes to growth factors which correlates with ploidy level, and this difference may be associated with the degree of maturation.
对培养的乳鼠和成年大鼠肝细胞在表皮生长因子（EGF）、胰岛素和胰高血糖素作用下进入S期和有丝分裂的能力进行了测定。两种细胞类型均以高产率和高纯度分离，并在无血清条件下于相同环境中培养。在分离时，乳鼠肝细胞均为二倍体，处于细胞周期的G1期。流式细胞术显示，成年大鼠肝细胞构成了一个多倍体水平混合的群体。受到刺激后，乳鼠和成年大鼠肝细胞在最短24小时的延迟期后均进入S期。对于乳鼠肝细胞，需要EGF，但其刺激作用依赖于胰岛素和/或胰高血糖素。相比之下，成年大鼠肝细胞仅对EGF有反应就进入S期；胰岛素和胰高血糖素并未显著增强其作用。在进入S期的最佳激素刺激下，大部分乳鼠肝细胞进行有丝分裂，而成年大鼠肝细胞仅观察到少数有丝分裂。因此，乳鼠和成年大鼠肝细胞对生长因子的反应存在差异，这与多倍体水平相关，且这种差异可能与成熟程度有关。
