Rapp L M, Thum L A, Anderson R E
Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030.
Exp Eye Res. 1988 Feb;46(2):229-38. doi: 10.1016/s0014-4835(88)80080-0.
Experiments were conducted to examine the possible interaction between retinal taurine depletion and environmental lighting in causing photoreceptor cell degeneration. Albino rats were raised from birth in either dim (2 lx) or relatively bright (300 lx) cyclic light. Beginning at weaning, half the animals from both light environments were taurine-depleted by treating them for 10 weeks with guanidinoethyl sulfonate as a 1% solution in their drinking water. The remaining animals were given ordinary tap-water and served as controls. In the 2 lx light environment, taurine depletion caused a decrease in electroretinogram (ERG) a- and b-wave amplitude of 36 and 46%, respectively; however, no photoreceptor cells were lost in this group. Tap-water controls kept in the 300 lx light environment had a 59- and 43% decrease in ERG a- and b-wave amplitude, respectively, and a 21% reduction in the number of photoreceptor cells. In contrast to the other groups, animals that were taurine-depleted in the 300 lx environment showed a marked retinal degeneration. ERG a- and b-wave amplitude was decreased by 94- and 89% respectively and there was a 62% loss of photoreceptor cells. The greatest cell loss occurred in the central superior region of the retina, in which the outer nuclear layer was typically reduced to one to two rows of nuclei. The results of a two-way analysis of variance applied to the data indicated that the effects of taurine depletion on the retina were greater in the 300 lx as compared with the 2 lx environment in terms of loss of photoreceptor cells and reduction in log ERG a- and b-wave amplitude. These findings demonstrate a synergism between environmental lighting and taurine depletion in causing photoreceptor cell degeneration.
进行了实验以研究视网膜牛磺酸缺乏与环境光照在导致光感受器细胞变性方面可能存在的相互作用。白化大鼠从出生起就饲养在昏暗（2勒克斯）或相对明亮（300勒克斯）的循环光照环境中。从断奶开始，来自两种光照环境的动物中有一半通过在饮用水中给予1%的胍基乙磺酸盐溶液处理10周而导致牛磺酸缺乏。其余动物给予普通自来水并作为对照。在2勒克斯光照环境中，牛磺酸缺乏分别导致视网膜电图（ERG）a波和b波振幅降低36%和46%；然而，该组中没有光感受器细胞丢失。饲养在300勒克斯光照环境中的自来水对照组ERG a波和b波振幅分别降低了59%和43%，光感受器细胞数量减少了21%。与其他组相比，在300勒克斯环境中牛磺酸缺乏的动物表现出明显的视网膜变性。ERG a波和b波振幅分别降低了94%和89%，光感受器细胞损失了62%。最大的细胞损失发生在视网膜的中央上区域，其中外核层通常减少到一到两排细胞核。对数据进行的双向方差分析结果表明，就光感受器细胞丢失以及log ERG a波和b波振幅降低而言，与2勒克斯环境相比，300勒克斯环境中牛磺酸缺乏对视网膜的影响更大。这些发现证明了环境光照与牛磺酸缺乏在导致光感受器细胞变性方面存在协同作用。
