1992 Fiscal Year Final Research Report Summary
Activation of liver microsomal glutathione S-transferase by oxidativc stress and its physiological role
| Project/Area Number |
03670147
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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 |
Pathological medical chemistry
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| Research Institution | University of the Ryukyus |
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Principal Investigator |
ANIYA Yoko Univ. of the Ryukyus, Medicine, Professor, 医学部, 教授 (90045055)
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| Co-Investigator(Kenkyū-buntansha) |
OJIRI Yoshihiko Univ. of the Ryukyus, Medicine, Assistant, 医学部, 助手 (00136904)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Glutathione Stransferase / Active oxygen / Liver microsomes / Glutathione / Oxidative stress / Lipid peroxide |
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| Research Abstract |
Activation of liver microsomal glutathione S-transferase (GST) by oxidative stress was investigated in vitro and in vivo. When the isolated liver was reperfused after a 90 min ischemia, microsomal GST, but not cytosolic, activety was significantly increased and the GSTm dimer protein was detected. Same phenomenon was also observed by perfusion of the liver with hydrogen peroxide or t-butylhydroperoxide. Furthermore, in phenobarbitaltreated liver in which the enzymes of cytochrome P-450 system were induced, GSTm activity was also increased and it was clarified that this increase was least due to an activation of GSTm by oxygen radicals produced via cytochrome P-450 system. In vitro experiments, it was demonstrated that fatty acid hydroperoxides as well as t-butylhydroperoxide also can activate the GSTm. Thus these data indicate that liver microsomal GST is activated byoxygen radicals including lipid peroxides generated during oxidative stress, detoxifying toxic metabolites formed by oxidative stress.
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