Horowitz I A, Norwint H, Hall E J
Radiology. 1975 Mar;114(3):723-6. doi: 10.1148/114.3.723.
In vitro cell cultures grown into plateau phase may be more suitable than exponentially growing cells as a model for tumor cell growth in vivo. Conditioned medium extracted from cells in plateau phase inhibits growth of log-phase cultures of either the same or a different cell line. Attempts to demonstrate that this inhibition is due to a heat-labile diffusible substance have failed. Conditioned medium extracted from plateau-phase cultures was effective in enhancing repair of potentially lethal damage following x irradiation. Cell survival is significantly increased following a six-hour postirradiation culture in conditioned medium as opposed to complete fresh medium.
进入平台期生长的体外细胞培养物可能比指数生长期的细胞更适合作为体内肿瘤细胞生长的模型。从处于平台期的细胞中提取的条件培养基可抑制同一细胞系或不同细胞系对数期培养物的生长。试图证明这种抑制是由于一种热不稳定的可扩散物质所致的尝试均告失败。从平台期培养物中提取的条件培养基在增强X射线照射后潜在致死性损伤的修复方面是有效的。与完全新鲜培养基相比，在条件培养基中进行六小时的照射后培养可显著提高细胞存活率。
