Ayala M N, Michael R, Söderberg P G
St. Erik's Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
Exp Eye Res. 2000 Apr;70(4):451-6. doi: 10.1006/exer.1999.0801.
The purpose of this study was to investigate the effects of repeated close-to-threshold ultraviolet radiation (UVR) doses in the rat lens. Sprague Dawley rats received two UVR exposures (lambda(max) = 300 nm, lambda0.5 = 10 nm) separated by different time intervals. The animals were unilaterally irradiated with 4 kJ m(2-1) UVR in each exposure. The intervals between both exposures were: 6 hr, 1 day, 3 days, 9 days and 30 days. At 1 week after the last exposure both lenses were removed, microphotographs were taken and intensity of forward light scattering was measured. Evaluating the difference between exposed and non-exposed eyes, the forward light scattering in the 6 hr and 1 day interval group was not significantly different. The most intense forward light scattering was found in the group that was allowed 3 days interval between exposures. Thereafter, the intensity of scattering decreased as the time interval between exposures increased. The lowest intensity of forward light scattering was detected in the 30 days interval group. Three days after a UVR exposure, the lens showed the highest sensitivity for a second UVR exposure. One month after the first exposure lenses undergo physiological repair and interactions between exposures seem to decrease.
本研究的目的是调查大鼠晶状体中重复接近阈值的紫外线辐射（UVR）剂量的影响。斯普拉格-道利大鼠接受两次UVR照射（λmax = 300 nm，λ0.5 = 10 nm），照射间隔时间不同。每次照射时，动物单侧接受4 kJ m-2的UVR照射。两次照射之间的间隔时间分别为：6小时、1天、3天、9天和30天。在最后一次照射后1周，取出双侧晶状体，拍摄显微照片并测量前向光散射强度。评估照射眼与未照射眼之间的差异，6小时和1天间隔组的前向光散射无显著差异。在照射间隔为3天的组中发现前向光散射最强。此后，随着照射间隔时间的增加，散射强度降低。在30天间隔组中检测到前向光散射强度最低。UVR照射3天后，晶状体对第二次UVR照射表现出最高的敏感性。首次照射1个月后，晶状体进行生理修复，照射之间的相互作用似乎减弱。
