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

在斯瓦尔巴特群岛捕获了两只北极熊、8只北极狐狸、6只胡须海豹、22只苍鸥、5只福尔马尔海豹、4只布鲁尼奇海豹、6只环斑海豹、5只冠海豹、6只海雀和7只斯瓦尔巴驯鹿。80 N)。动物和鸟类肝脏中储存了大量维生素A[23,300(北极熊，n=2)，18,439*2,314(北极狐，n=8)，5956*5857(胡海豹，n=6)，1,551*2,486(环斑海豹，n=6)，921*264(Svalbard reindeer，n=7)，4,710*3,164(灰鸥，n=22)，1,589*225(Bruenich‘s guihemot，n=4)和1183*589(海雀，n=6)nmole视黄酸酯/克湿组织]。维生素A的很强的自发荧光来自肝脏中的非实质细胞。这些细胞与氯化金呈阳性反应，染色呈黑色。在电子显微镜下，这些细胞存在于Disse的窦周间隙，胞浆内含有大量的脂滴。这些发现表明，这些维生素A储存细胞是肝星状细胞，而在北极地区处于食物网较高位置的北极动物在肝星状细胞中具有发育良好的维生素A储存机制。

Two polar bears, 8 Arctic foxes, 6 bearded seals, 22 glaucous gulls, 5 fulmars, 4 Bruenich's guillemots, 6 ringed seals, 5 hooded seals, 6 puffins, and 7 Svalbard reindeers were caught in the Svalbard archipelago (situated at lat. 80 N). Fresh organs, namely, the liver, kidney, spleen, lung, and jejunum were investigated with gold chloride staining, fluorescence microscopy for autofluorescence of vitamin A, hematoxylin and eosin staining, azan staining, Ishii-Ishii's silver impregnation, transmission electron microscopy and high-performance liquid chromatography.The mammals and birds stored a large amount of vitamin A in the liver [23,300 (polar bear, n=2), 18,439*2,314 (Arctic fox, n=8), 5956*5857 (bearded seal, n=6), 1,551*2,486 (ringed seal, n=6), 921*264 (Svalbard reindeer, n=7), 4,710*3,164 (glaucous gull, n=22), 1,589*225 (Bruenich's guiHemot, n=4), and 1183*589 (puffin, n=6) nmole retinyl ester/g wet tissue]. Very strong autofluorescence of vitamin A emanated from the non-parenchymal cells in the liver. These cells showed positive reaction with gold chloride and stained black. Electronmicroscopically these cells existed in the perisinusoidal space of Disse and contained many lipid droplets within the cytoplasm. These anamals showed no hepatic fibrosis though they are in naturally occurred hypervitaminosis A.These findings suggest that these vitamin A-storihg cells are hepatic stellate cells and the Arctic animals that exist in a higher position of the food web in the Arctic area have well-developed vitamin A-storing mechanisms in the hepatic stellate cells.