| Project/Area Number |
09470491
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical pharmacy
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| Research Institution | Chiba University |
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Principal Investigator |
HORIE Toshiharu Faculty of Pharmaceutical Sciences, Chiba University, Professor, 薬学部, 教授 (90120154)
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| Co-Investigator(Kenkyū-buntansha) |
MASUBUCHI Yasuhiro Faculty of Pharmaceutical Sciences, Chiba University, Lecturer, 薬学部, 講師 (10209455)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥9,300,000 (Direct Cost: ¥9,300,000)
Fiscal Year 1999: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥6,700,000 (Direct Cost: ¥6,700,000)
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| Keywords | chemiluminescence / hepatocyte / hepatotoxicity / oxidative stress / lipid peroxidation / glutathione / reactive metabolite / cytochrome P450 / 非ステロイド系抗炎症薬 / ジクロフェナック / ATP / サリチル酸 / ジヒドララジン |
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| Research Abstract |
The drug-induced hepatotoxicity was studied on the oxidative stress and reactive metabolites, using liver microsomes, isolated hepatocytes, primary cultured hepatocytes and liver tissues.
The chemiluminescence was used to investigate the drug-induced oxidative stress. The chemiluminescence-HPLC system was set up and we tried to measure the lipid peroxides produced during the drug metabolism. And phosphatidyl choline hydroperoxide (PCOOH) was detected in the rat liver microsome and isolated hepatocyte suspension incubated with ethacrynic acid. It was observed that PCOOH was produced earlier than the thiobarbituric acid reactive substances (TBARS) formation. The ultraweak chemiluminescence was shown to be emitted directly from the liver microsomes and isolated hepatocytes incubated with ethacrynic acid. This was accompanied by the LDH release from the isolated hepatocytes. Further, we set up the organ chemiluminescence system and succeeded in detecting the ultraweak chemiluminescence emitted from the rat liver perfused with ethacrynic acid. This result substantiated the ethacrynic acid-induced oxidative stress in the liver. These results obtained from the chemiluminescence detection systems were found to be related closely with the alteration in glutathione. Thus the oxidative stress due to the drug metabolism was shown to be detectable by the chemiluminescence system with high sensitivity and specificity.
Dihydralazine is known to cause the immunohepatitis and CYP1A2 is reported as a target protein of its reactive metabolite. In addition, CYP3A4 was found to be its target protein in rat and human liver microsomes. The imipramine- and mianserin-induced hepatotoxicity was shown to be closely related with their reactive metabolites. The diphenylamine structure was found to play an important role in the nonsteroidal anti-inflammatory drug-induced hepatotoxicity. The NSAIDs with diphenylamine structure were shown to be uncouplers of oxidative phosphorylation.
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