Lett J T, Cox A B, Lee A C
Radiat Res Suppl. 1985;8:S201-7.
Two sets of observations on cataractogenesis in the New Zealand white (NZW) rabbit (Oryctolagus cuniculus) following localized exposure of optic and proximate tissues to heavy ions are reported. The experiments involved measurements of lenticular opacification in young (ca. 9 weeks old) rabbits caused by graded doses (0.5-5.0 Gy) of 460 MeV/u (incident energy) 56Fe ions and the effects of animal age (9 +/- 0.3 week, 1 +/- 0.5 year, and 4.5 +/- 1.3 year) on lenticular opacifications caused by 9 Gy of 400 MeV/u (incident energy) 20Ne ions. In substantiation of earlier results from NZW rabbits exposed to other low- and high-LET radiations, there was a dose-dependent onset of cataractogenesis following 56Fe-ion irradiation, with the highest doses causing the earliest appearance of cataracts. The level of stationary cataracts was also dependent on dose, and preliminary estimates of RBE yield values comparable to those found at similar doses (0.5-5.0 Gy) by others with populations of cultured cells. With increasing age at the time of exposure to 20Ne ions, the onset of lenticular opacification was delayed progressively and the level of stationary cataracts was reduced, but the onset and progression of late cataractogenesis was most rapid in the oldest group of animals. A discussion of the use of cataract measurements in risk assessment is included in this article.
报告了两组关于新西兰白兔（Oryctolagus cuniculus）在视神经及邻近组织局部暴露于重离子后白内障形成的观察结果。实验包括测量年轻（约9周龄）兔子因不同剂量（0.5 - 5.0 Gy）的460 MeV/u（入射能量）56Fe离子导致的晶状体混浊情况，以及动物年龄（9 ± 0.3周、1 ± 0.5岁和4.5 ± 1.3岁）对9 Gy的400 MeV/u（入射能量）20Ne离子所致晶状体混浊的影响。为证实先前新西兰白兔暴露于其他低LET和高LET辐射的结果，56Fe离子照射后白内障形成存在剂量依赖性起始，最高剂量导致白内障最早出现。静止期白内障的程度也取决于剂量，且对相对生物效应（RBE）产额值的初步估计与其他人在相似剂量（0.5 - 5.0 Gy）下对培养细胞群体所发现的值相当。随着暴露于20Ne离子时年龄的增加，晶状体混浊的起始逐渐延迟，静止期白内障的程度降低，但在最年长的动物组中晚期白内障形成的起始和进展最为迅速。本文还包括了关于在风险评估中使用白内障测量的讨论。
