1995 Fiscal Year Final Research Report Summary
ECHOTOXICOLOGY OF ULTRA VIOLET RADIATION ON EARTH ENHANCED BY DEPLETION OF STRATOSPHERIC OZONE
| Project/Area Number |
05453199
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
環境保全
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KAZUSAKA Akio Hokkaido Univ., Graduate School of Veterinary Medicine, Assoc. Pro., 大学院獣医学研究科, 助教授 (00002113)
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| Co-Investigator(Kenkyū-buntansha) |
MASUDA Makihiko Hokkaido Univ., Graduate School of Veterinary Medicine, Assoc. Pro., 大学院獣医学研究科, 助教授 (00001719)
FUJITA Shoichi Hokkaido Univ., Graduate School of Veterinary Medicine, Pro., 大学院獣医学研究科, 教授 (10143314)
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| Project Period (FY) |
1993 – 1995
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| Keywords | Echotoxicology / Stratospheric ozone / Chloroplast / Chlorophyll / Singlet oxygen / Luminescence spectrum of chlorophyll / Peroxidation of thyrakoid membrane / Induction of protease |
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| Research Abstract |
The depletion of of stratospheric ozone is considered to enhance UV radiation on the earth and to destroy its echosystem. Echotoxicolgy of UV radiation was studied for plants.
A.The chloroplast fraction of a clover, Trifolium, was found to catalyze the demethylation of imipramine for its starting period. Chlrophyll was suggested to be an active compornent and to lose its catalytic activity spontaneously.
B.A commercial chlorophyll a was used for catalytic demethylation of imipramine under radiation of light above 500nm, indicating that it produces singlet oxygen as a reation intermediate.
C.In interest to utilize chlorophyll a as photocatalyst, it was found to be stable in nonpolar solvent but decomposed partially on MgO.Chlorophyll a impregnated on MgO gave a hydroxy radical under visible light, indicating its usefulness as photocatalyst.
D.Spinach thyarkoid membrane was radiated by UV-A light in interest for its photodamage to plants. The radiation did not affect the amount of chlorophyll contained in it, but its luminescence spectra was changed indicating the photostress of thyrakoid membrane. Photoformation of singlet oxygen was observed in radiation of UV-A,but was deactivated with radiation time. Protease inhibitor stopped its deactivation, suggesting an induction of some kind of protease by UV-A radiation.
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