Mechanisms of absorption, transport, and storge of vitamin A-by using rats and polar animals-

1996年8月至9月，在斯瓦尔巴群岛捕获了7只斯瓦尔巴驯鹿、3只环斑海豹、2只须海豹、4只白嘴鸥、3只海鸠和1只海雀。用氯化金染色、维生素A自身荧光荧光显微镜、苏丹3脂质染色、苏木精和伊红染色、Azan染色、石井和石井浸银法、透射电镜等方法对各器官即肝、肾、肺、空肠、脾和皮肤进行观察。北极的动物和鸟类在肝星状细胞中储存了大量的维生素a。只有少量的维生素a存在于其他器官：肾脏、空肠、脾脏、肺和皮肤。另一方面，正常大鼠的肝外星状细胞被证明在肾脏、肺、脾和肠中储存维生素A。这些结果表明，北极动物和鸟类在生理条件下可以在肝星状细胞中储存大量维生素a。这些数据还表明，北极动物和鸟类体内的类维甲酸结合蛋白等分子机制在维生素A的储存中起着关键作用。利用这些分子机制，将开发预防维生素A过多症的方法，维生素A过多症是维生素A治疗恶性疾病（如白血病）的副作用。

Seven Svalbard reindeers, 3 ringed seals, 2 bearded seals, 4 glaucous gulls, 3 Brunnich's guillemots, and 1 puffin were caught in the Svalbard archipelago from August through September, 1996. Fresh each organs, namely, the liver, kidneys, lungs, jejunum, spleen, and skin were investigated with gold chloride staining, fluorescence microscopy for autofluorescence of vitamin A,Sudan 3 lipid staining, hematoxylin and eosin staining, Azan staining, Ishii and Ishii's silver impregnation method, and transmission electron microscopy.The Arctic animals and birds store a large amount of vitamin A in hepatic stellate cells. Only a small amount of vitamin A existed in other organs : kidneys, jejunum, spleen, lungs, and skin. On the other hand, extrahepatic stellate cells in normal rats were demonstrated to store vitamin A in the kidneys, lungs, spleen, and intestine.These results indicated that the Arctic animals and birds can store a huge amount of vitamin A in hepatic stellate cells in physiological conditions. These data also indicated that the molecular mechanisms such as retinoid-binding proteins in the Arctic animals and birds play pivotal roles in their vitamin A storage. Applying these molecular mechanisms the prevention methods will be developed for hypervitaminosis A as a side effect of vitamin A treatment to malignant diseases such as leukemia.