Blomhoff R, Green M H, Berg T, Norum K R
Institute for Nutrition Research, School of Medicine, University of Oslo, Norway.
Science. 1990 Oct 19;250(4979):399-404. doi: 10.1126/science.2218545.
The requirement of vitamin A (retinoids) for vision has been recognized for decades. In addition, vitamin A is involved in fetal development and in the regulation of proliferation and differentiation of cells throughout life. This fat-soluble organic compound cannot be synthesized endogenously by humans and thus is an essential nutrient; a well-regulated transport and storage system provides tissues with the correct amounts of retinoids in spite of normal fluctuations in daily vitamin A intake. An overview is presented here of current knowledge and hypotheses about the absorption, transport, storage, and metabolism of vitamin A. Some information is also presented about a group of ligand-dependent transcription factors, the retinoic acid receptors, that apparently mediate many of the extravisual effects of retinoids.
数十年来，维生素A（类视黄醇）对视力的重要性已为人所知。此外，维生素A参与胎儿发育以及一生中细胞增殖和分化的调节。这种脂溶性有机化合物不能由人体自身合成，因此是一种必需营养素；尽管每日维生素A摄入量有正常波动，但一个调节良好的运输和储存系统能为组织提供适量的类视黄醇。本文概述了有关维生素A吸收、运输、储存和代谢的现有知识和假说。还介绍了一些关于一组配体依赖性转录因子即视黄酸受体的信息，这些受体显然介导了类视黄醇的许多视觉外效应。
