Structural and biochemical changes in vitamin A--deficient rat retinas.
Structural and biochemical changes in vitamin A--deficient rat retinas.
复制标题
维生素 A 缺乏的大鼠视网膜的结构和生化变化。
DOI：
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发表时间：
1979
影响因子：
4.4
通讯作者：
J. G. Bieri
中科院分区：
文献类型：
--
作者：
L. Carter;T. Kuwabara;P. O’Brien;J. G. Bieri
研究了在低水平的循环照明（1.5至2英尺烛光）下，视紫红质和视蛋白的水平与维生素A缺乏大鼠视网膜中视网膜结构的维持的关系。9周时，缺乏视网膜中的视紫红质水平下降至对照组的约20%，并且在缺乏饮食的情况下，该水平一直保持到39周。视蛋白水平以较慢的速率下降，但在32周时达到对照水平的约20%。尽管视紫红质水平下降，但直到缺乏16周才观察到椎间盘结构的明显恶化，此时视蛋白水平已经下降到对照组的60%至70%。光感受器外节的结构破坏最初定位在远端三分之一的光盘。维生素A缺乏的视网膜视杆细胞变性先于视锥细胞变性。大多数的杆和锥坚持在后视网膜在23周的缺乏饮食，然而，到40周，只有11%的杆核仍然存在。相比之下，约63%的锥细胞核存在于40周的缺陷。光感受器细胞受到的影响，在更大程度上在下半球比在上级半球的眼睛。
The levels of rhodopsin and opsin were investigated in relation to the maintenance of retinal structure in retinas of vitamin A--deficient rats in low levels of cyclic illumination (1.5 to 2 foot-candles). Rhodopsin levels decreased in the deficient retinas to approximately 20% of control at 9 weeks, and this level was retained through 39 weeks on the deficient diet. Opsin levels decreased at a slower rate but reached about 20% of control levels at 32 weeks. Despite the decrease in rhodopsin levels, obvious deterioration of disc structure was not observed until 16 weeks of deficiency, when opsin levels had already decreased to 60% to 70% of control. The structural disruption of photoreceptor outer segments was localized initially in discs of the distal third. Rod cell degeneration preceded cone cell degeneration in vitamin A--deficient retinas. Most of the rods and cones persisted in the posterior retina at 23 weeks on the deficient diet; however, by 40 weeks, only 11% of the rod nuclei remained. In contrast, about 63% of the cone nuclei were present at 40 weeks of deficiency. The photoreceptor cells were affected by the deficiency to a greater extent in the inferior hemisphere than in the superior hemisphere of the eye.