Gould M N, Cathers L E, Clifton K H, Howard S, Jirtle R L, Mahler P A, Mulcahy R T, Thomas F
Br J Cancer Suppl. 1984;6:191-5.
Radiation survival curves are presented for several normal parenchymal cell types irradiated in situ or in vitro. The data presented indicate that the in situ survival parameters for a specific cell type cannot be simply extrapolated from the results of either in vitro assays or rapid in vivo clonal transplantation assays. The data suggest that the D0 and terminal slope of in vitro survival curves can reflect those parameters for cells left in situ, but the shoulder width and the n value cannot. This appears to be due to the inability of the in vitro environment to support two major forms of repair that occur in situ, i.e. the "contact effect" and in situ repair (ISR). ISR is a form of potentially lethal damage repair (PLDR) that occurs when certain cells are allowed to remain in situ following irradiation. ISR is characterized by an increased shoulder in the survival curve without a change in slope and it has been observed in rat mammary, thyroid and liver epithelia.
本文给出了几种在原位或体外照射的正常实质细胞类型的辐射存活曲线。所呈现的数据表明，特定细胞类型的原位存活参数不能简单地从体外试验或快速体内克隆移植试验的结果中推断出来。数据表明，体外存活曲线的D0和终末斜率可以反映原位细胞的这些参数，但肩宽和n值则不能。这似乎是由于体外环境无法支持原位发生的两种主要修复形式，即“接触效应”和原位修复（ISR）。ISR是一种潜在致死性损伤修复（PLDR）形式，当某些细胞在照射后留在原位时发生。ISR的特征是存活曲线的肩部增加而斜率不变，并且已在大鼠乳腺、甲状腺和肝上皮中观察到。
