Dark adaptation and experimental human vitamin A deficiency
Dark adaptation and experimental human vitamin A deficiency
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DOI：
10.1152/ajplegacy.1940.130.4.651
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发表时间：
1940-10-01
影响因子：
--
通讯作者：
Mandelbaum, J
中科院分区：
文献类型：
--
作者：
Hecht, S;Mandelbaum, J
17.在他们逗留之前，期间和之后，测量了17只年轻[雄性][雄性]的黑暗适应。缺甲饮食对视锥细胞和视杆细胞的视功能均有影响。锥阈值上升小于杆阈值，但它们的行为近似。并联这些变化的最佳单一标准是在黑暗中30分钟后的最终视杆阈值。当受到缺乏饮食，大多数人（14 17）作出反应，立即和明确无误的上升，在视觉阈值持续的饮食。另外3例受试者分别需要22、55和60天才能给出明显和持续的阈值升高。所有受试者均未出现任何皮肤症状，只有2名受影响最严重的受试者记录了其视觉阈值升高的主观意识。单次大剂量维生素可使某些个体的视觉阈值部分恢复。A.回收的程度各不相同。复苏从来都不是完全的，而且总是暂时的。从缺乏A的饮食中永久恢复是缓慢的，需要周和月。最快的受试者在6周内恢复正常。最慢的保持高阈值超过3个MOS，但一年后就完全恢复了。通过补充其他维生素来影响A缺乏饮食期间和之后的视觉反应。只得到了负面的结果。
Measurements of the dark adaptation of 17 young [male][male] made before, during, and after their stay on a vit. A-deficient diet show that cone and rod visual functions are both affected by the diet. The cone thresholds rise less than the rod thresholds, but their behavior is approx. parallel. The best single criterion of these changes is the final rod threshold after 30 min. in the dark. When subjected to the deficient diet, most individuals (14 of 17) responded by an immediate and unmistakable rise in visual threshold which continued for the duration of the diet. The other 3 subjects required 22, 55 and 60 days respectively before giving a clear and continuous rise in threshold. None of the subjects showed any skin symptoms, and only the 2 most extremely affected individuals recorded a subjective awareness of their raised visual thresholds. Partial recovery of the visual threshold was accomplished in some individuals by single large doses of vit. A. The extent of the recoveries was variable. The recoveries were never complete and were always temporary. Permanent recovery from an A-deficient diet was slow, requiring wks. and mos. The fastest subject returned to normal in 6 wks.; the slowest maintained a high threshold for over 3 mos., but had recovered completely after a yr. Efforts to influence the visual responses during and after the A-deficient diet by supplementation with other vits. yielded only negative results.