IMAI Katsuyuki Akita University, Department of Anatomy, Research Associate, 医学部, 助手 (80006741)
SATO Mitsuru Akita University, Department of Anatomy, Research Associate, 医学部, 助手 (60226008)
BERG Trond University of Oslo, Department of Cell Biology, Professor, 医学部, 教授
BLOMHOFF Rune University of Oslo, Institute for Nutrion Research, Professor, 医学部, 教授
NORUM Kaare R. University of Oslo, Institute for Nutrion Research, Professor, 医学部, 教授
|Budget Amount *help
¥6,900,000 (Direct Cost : ¥6,900,000)
Fiscal Year 1998 : ¥2,600,000 (Direct Cost : ¥2,600,000)
Fiscal Year 1997 : ¥4,300,000 (Direct Cost : ¥4,300,000)
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.