| Project/Area Number |
63571061
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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 |
Biological pharmacy
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| Research Institution | Tokyo University of Pharmacy and Life Science |
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Principal Investigator |
HORIE Toshiharu Tokyo College of Pharmacy, Dept. of Biopharm., Assistant Professor, 薬学部, 講師 (90120154)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHI Masahiro Tokyo college of Pharmacy, Dept. of Biopharm., Associate Professor, 薬学部, 助教授 (20012669)
AWAZU Shoji Tokyo College of Pharmacy, Dept. of Biopharm., Professor, 薬学部, 教授 (60012621)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1990: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1989: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1988: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Drug Toxicity / Hepatotoxicity / Lipid Peroxidation / Glutathione / Hepatocyte / Liver Microsome / Fluorescent Substance / Acetaminophen / 蛋白重合体 / 四塩化炭素 / 肝ミクロゾ-ム / 蛍光物質 / 肝ミクロゾーム / 蛍光寿命 |
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| Research Abstract |
Drug-induced lipid peroxidation was investigated in vitro and in vivo. 1. The method to determine glutathione was set up using HPLC which was supplied by this grant. The determination was carried out by labeling eluted glutathione with o-phthalaldehyde.
2. Lipid peroxidation was evaluated by thiobarbituric acid reactive substances (TBA-RS), fluorescent substances and high molecular weight protein aggregates. Fluorescent substances formed in peroxidized microsomes of rat liver were characterized by measuring fluorescence lifetime.
Fluorescent substances were found to have at least three different fluorescence lifetimes. This was the same in microsomal proteins and lipids. Microsomal enzymes decreased their activities during lipid peroxidation and membrane fluidity also decreased.
3. Acetaminophen was orally administered to rats. Plasma glutamic-oxaloacetic transaminase (GOT) increased and TBA-RS in liver homogenates slightly increased. When diethylmaleate was injected intraperitoneally to rats before acetaminophen administration, fluorescent substances and high molecular weight protein aggregates were found in liver microsomes. This indicates that glutatione plays an important role in acetaminophen-induced lipid peroxidation. The same was observed in carbon tetrachloride and adriamycin. These indices to evaluate lipid peroxidation were found to be useful to detect in vivo lipid peroxidation.
4. Effects of acetaminophen on isolated hepatocytes were investigated. Hepatocytes were incubated with acetaminophen. When TBA-RS was produced, cell viability decreased. Simultaneously, GOT in the medium increased and intracellular glutathione decreased. At higher concentration of acetaminophen, TBA-RS formation was depressed and cell viability was not decreased,
which was probably due to the antioxidant effect of acetaminophen itself. Thus, this study showed that lipid peroxidation played an important role in acetaminophen-induced hepatotoxicity.
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