| Project/Area Number |
59540474
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物発生・生理学
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| Research Institution | Hyogo College of Medicine |
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Principal Investigator |
SUZUKI Tatsuo Faculty of Medicine, Hyogo College of Medicine, 医学部, 助手 (90068544)
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| Project Period (FY) |
1984 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1986: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1985: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1984: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Visual pigment / Vitamin <A_1> / Vitamin <A_2> / Retinal / 3-Dehydroretinal / Rhodopsin / ポルフィロプシン |
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| Research Abstract |
The purpose of this project is to investigate the general existence of vitamin <A_1> - <A_2> converting system in animals by using crayfish and mouse.
The crayfish Procambarus clarkii, which has vitamin <A_2> -pigment, was kept in various conditions of light and temperature. 3-Dehydroretinal accumulated in the retina when the animal was kept at 10゜C. 3-Dehydroretinal was converted to retinal when the animal was kept at 25゜C in the presence of light but not in the dark. The results show that the crayfish has the vitamin <A_1> - <A_2> converting system in the retina and that the temperature is the most important factor regulating the system.
We made vitamin A-deficient mouse. The mouse was injected intraperitoneally with vitamin <A_2> . Vitamin <A_2> was rapidly incorporated into the liver as palmitic acid ester and gradually into the retina as 3-dehydroretinal. 3-Dehydroretinal accounted for 95% of the total chromophore of visual pigment in the retina. The high proportion of 3-dehydroretinal was observed also in the long term experiment which was continued for 6 weeks. When the vitamin A-deficient mouse was injected with a mixture of vitamins <A_2> and <A_1> , <A_2> / <A_1> ratio in the retina was far lower than that in the liver. These results show that vitamin <A_2> is not converted to <A_1> in the mouse and used less efficiently than <A_1> for the synthesis of visual pigment.
As recent reports suggest the conversion of vitamin <A_1> into <A_2> in the human skin, further studies on the vitamin <A_1> - <A_2> converting system are required in mammals.
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