Lipoprotein metabolism in eel.
| Project/Area Number |
07660274
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fisheries chemistry
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| Research Institution | Kagoshima University |
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Principal Investigator |
HAYASHI Seiichi Faculty of Fisheries, Kagoshima University, 水産学部, 教授 (80041721)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1995: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | lipoprotein / primary culture of hepatocytes / HDL receptor / thyroxine / eel / docosahexaenoic acid / flow cytometer / fluorescent labelling / リポタンパク質 / レセプター / 培養細胞 / 肝細胞 / フローサイトメモリー / 脂質合成 |
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| Research Abstract |
Plasma lipid concentration of fishes such as eel, carp and raibowtrout is several times higher than that of familial hypercholesterolemia and hypertriglycemia of human beings, but the reason is unknown. Studies of lipoprotein metabolism in fish are conducted to solve the question described above since most of plasma lipid exist as components of lipoproteins.
Four major subjects are studied to investigate lipoprotein metabolism using cultured eel hepatocytes. 1. HDL receptor of eel hepatocytes was investigated using HDL labelled with a lipophilic fluorescent dye, which was synthesized in our laboratory. It was found that HDL receptor existed on eel hepatocytes and the Kd value for HDL was about 20 mug HDL / ml. Furthermore, HDL stimulated a lipoprotein synthesis and secretion in the hepatocytes. 2. It is a remarkable characteristic of fish oil that rather high amount of polyunsaturated fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid is contained in fish oils. Then effect of DHA on lipoprotein synthesis and secretion was investigated. DHA stimulated synthesis of lipoprotein, triacylglycerol and cholesterol, but remarkably inhibited the secretion of lipoprotein. 3. It is known that migration of fishes such as eel has a relationship with thyroid hormone. Effect of T4 on lipoprotein synthesis was investigated. T4 stimulated lipogenesis as well as lipoprotein synthesis. 4. Lipoprotein synthesis and serum lipoproteins of silver eel, which migrates from the river to the sea for spawning, were compared with those of cultured eel, which is sexually immature. Silver eel hepatocytes actively synthesized lipoprotein compared to hepatocytes of cultured eel and the secreted lipoprotein by silver eel hepatocytes had higher ratio of lipid than that by cultured eel hepatocytes. Contrary to secreted lipoprotein, serum lipoproteins of silver eel had lower lipid ratio than those of cultured eel.
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Report
(3 results)
Research Products
(13 results)
