Tao F, Medvedovsky C, David J, Broglio T, Powers-Risius P, Alpen E L, Worgul B V
Department of Ophthalmology, Columbia University, New York, NY 10032.
Int J Radiat Biol. 1993 Jul;64(1):103-11. doi: 10.1080/09553009314551151.
Lenses of mice irradiated with 250 MeV protons, 670 MeV/amu 20Ne, 600 MeV/amu 56Fe, 350 MeV/amu 56Fe, 600 MeV/amu 93Nb or 593 MeV/amu 139La ions were evaluated by analysing cytopathological indicators which have been implicated in the cataractogenic process. The LETs ranged from 0.39 to 953 keV/microns and the fluences from 1.31 x 10(3)/mm2 to 5.12 x 10(7)/mm2. The lenses were assessed 64 weeks post-irradiation in order to observe the late effects of LET and dose on the target cell population of the lens' epithelium. Our studies showed that growth-dependent pathological changes occurred at the cellular level as a function of dose and LET. For a given particle dose, as the LET rose, the number of abnormal mitotic figures, micronuclei frequency, and the disorganization of meridional rows increased to a maximum and then reached a plateau or decreased. For particles of the same LET, the severity of meridional rows disorganization and micronuclei frequency increased with increasing dose. The numbers of cells surviving at late times post-irradiation were comparable with those of controls. In addition, the cellular density was similarly unaffected. These observations are consistent with the current theory of the mechanism of radiation cataractogenesis which posits that genomic damage to the epithelial cells surviving the exposure is responsible for opacification.
通过分析与白内障形成过程相关的细胞病理学指标，对受250兆电子伏质子、670兆电子伏/原子质量单位的20氖、600兆电子伏/原子质量单位的56铁、350兆电子伏/原子质量单位的56铁、600兆电子伏/原子质量单位的93铌或593兆电子伏/原子质量单位的139镧离子辐照的小鼠晶状体进行了评估。传能线密度范围为0.39至953千电子伏/微米，注量范围为1.31×10³/mm²至5.12×10⁷/mm²。在辐照后64周对晶状体进行评估，以观察传能线密度和剂量对晶状体上皮靶细胞群体的后期影响。我们的研究表明，与生长相关的病理变化在细胞水平上随剂量和传能线密度而发生。对于给定的粒子剂量，随着传能线密度升高，异常有丝分裂图像数量、微核频率以及子午线行的紊乱程度增加至最大值，然后达到平稳期或下降。对于相同传能线密度的粒子，子午线行紊乱的严重程度和微核频率随剂量增加而增加。辐照后期存活的细胞数量与对照组相当。此外，细胞密度同样未受影响。这些观察结果与当前辐射性白内障形成机制的理论一致，该理论认为，暴露后存活的上皮细胞的基因组损伤是导致晶状体混浊的原因。
