Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATL INST INFECTIOUS DISEASES  

Reactions of thioureylene antithyroid drugs (1-methyl-2-mercaptoimidazole and carbimazole) with hypochlorous acid (HOCl) and superoxide were followed optically and products were analyzed by,mass spectrometry. 1-Methyl-2-mercaptoimidazole (MMI) and carbimazole reacted rapidly with HOCl with a rate constant of 1 X 10(7) and 7 X 10(6) M(-1)s(-1), respectively. The characteristic spectrum assigned to MMI disulfide appeared immediately after addition of HOCl, followed by a slow conversion to a final spectrum. The conversion was dependent upon the ratio of HOCl to MMI and both antithyroid drugs uptake 3 moles HOCl for complete conversion. A similar sequence of spectral changes was also observed when the HOCl was replaced by myeloperoxidase (MPO)/H2O2/Cl- system. The final oxidation product of MMI and carbimazole with HOCl and superoxide was 1-methylimidazole.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Visible light irradiation of 18 muM bilirubin ditaurate (BR-DT) at pH 7.0 for 30 min showed a 10% decrease in absorbance at 445 nm. When the reaction was carried out in the presence of a trace amount of uroporphyrin (UP), the spectrum of BR-DT disappeared without a concomitant formation of biliverdin. Photooxidation products were confirmed to be dipyrrole-containing compounds. Photobleaching of BR-DT was accelerated by the increasing concentration of UP and was inhibited, when UP was replaced by Cu2+ UP. Formation of 2,2,6,6-tetramethylpiperidine N-oxyl through the irradiation of UP was diminished by sodium azide, a potent scavenger of singlet oxygen. The efficiency of singlet oxygen formation through visible light irradiation was in the order UP, coproporphyrin > Cu2+ UP. Both bilirubin and BR-DT bound to human serum albumin (HSA) were photooxidized effectively in the presence of UP. The results indicate that irradiation of UP produces singlet oxygen with high efficiency which then rapidly oxidizes free and conjugated bilirubin.

DOI： 10.1080/10715760310001600381

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Language：Japanese   Publisher：(公社)日本生化学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SWETS ZEITLINGER PUBLISHERS  

Purpose. To investigate the effect of bucillamine for prevention of increasing blood-retinal barrier (BRB) permeability in streptozotocin (STZ)-induced diabetic rats.
Methods. The groups included control and STZ-induced diabetic rats treated with or without bucillamine. Six months after intervention, the concentrations of reduced and oxidative glutathione (GSH and GSSG) in the retina were measured biochemically. In addition, vitreous fluorescein, which leaks from the vessels after intravenous injection of fluorescein sodium, was measured to evaluate BRB permeability. To evaluate the scavenging ability against the reactive oxygen species (ROS) in vitro, the second-order rate constant for the reaction of bucillamine with ROS was estimated from the kinetics based on the rate constant for the reaction of ROS.
Results. The BRB permeability was significantly higher (p = 0.01) in diabetic rats not treated with bucillamine, and bucillamine inhibited the BRB permeability. The GSH concentration and the GSH/GSSG ratio in the retinas decreased in diabetic rats not treated with bucillamine; bucillamine inhibited the decrease of the GSH concentrations. The ROS scavenging activity of bucillamine was similar with that of GSH.
Conclusions. In diabetic retinas, oxidative stress might increase, which may be one of the causes of BRB breakdown. The antioxidant effects of bucillamine might take part in inhibition of increased permeability of the BRB in diabetes.

DOI： 10.1076/ceyr.25.1.1.9962

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SWETS ZEITLINGER PUBLISHERS  

Purpose. We investigated the inhibitory effects of bucillamine on formation of laser-induced choroidal neovascularization (CNV) in a rat model.
Methods. Bucillamine administration (approximately 150 mg/kg/day) was started 1 week before photocoagulation and continued to the end of the study. Control groups received drinking water. Two weeks after photocoagulation, choroidal neovascularization development was evaluated using simultaneous fluorescein and indocyanine green angiography, and the maximal thickness of the lesions was measured histologically.
Results. The incidence of CNV formation was 99.5 +/- 0.2% [mean +/- standard deviation (SD)] in control rats and 64.3 +/- 15.1% with bucillamine (P < 0.01). Histological study showed that the thickness of the CNV lesions was 23.4 ± 6.5 μm (mean ± SD) in the bucillamine-treated rats, which was significantly decreased compared to that in controls (60.8 ± 9.2 μm) (P < 0.01).
Conclusions. Our results suggest that bucillamine may inhibit the development of laser-induced CNV in rats.

DOI： 10.1076/ceyr.24.1.1.5434

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC  

Redox properties of metallothioneins (MTs) and Cu in the cytosol from Long-Evans Cinnamon (LEC) rat livers 13 weeks after birth were investigated. MTs from LEC rat livers contain 8 g atoms of Cu and 1 g atom of Zn per mole of protein (Cu(I)(8)-MTs). Titration of Cu(I)(8)-MTs with CuCl2 indicates that Cu(I)(8)-MTs were able to reduce further 2-g atoms of cupric ions per mole MTs as bound form. Hg2+-induced hydroxyl radical generation from Cu(I)(8)-MTs was demonstrated by ESR using the spin trap, 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The intensity of DMPO-OH signal from Cu-loaded MTs was increased with the increasing number of Cu in MTs. The used cytosol fraction contained 1.37 mM total Cu and 5 mM DTNB titrable-SH groups has a potential to reduce 2 mM CuCl2. No ESR signal due to Cu2+ was also detected with LEC rat liver cytosol, whereas strong Cu2+ signal appeared by the addition of HgCl2. The rate constants for the reaction of Cu(I)(8)-MTs with superoxide and hydroxyl radicals were estimated to be 2 x 10(6) and greater than or equal to 10(12) M(-1)s(-1), respectively, from competition kinetics. Cu2+-catalyzed oxidation of DNA was strongly inhibited both in the presence of Cu-unsaturated MTs and GSH. The results suggest that Cu(I)(8)-MTs from LEC rat livers just before hepatitis still act as antioxidants. (C) 2001 Academic Press.

DOI： 10.1006/abbi.2000.2233

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：W S MANEY & SONS LTD  

Calf thymus DNA was treated with authentic HOCl, and hypohalous acid-generating systems. This caused a decrease in fluorescence of ethidium-DNA complexes when ethidium bromide was subsequently added to the DNA. The fluorescence continued to decrease up to 30 min after adding HOCl. Loss in fluorescence was proportional to the concentration of HOCl and was complete when a 3-fold excess of HOCl was added to the DNA. No significant decrease in the fluorescence was observed when the chlorination was carried out in the presence of a concentration of monochlorodimedone (MCD) equivalent to that of HOCl. MCD is known to react stoichiometrically with HOCl. The decrease in fluorescence was completely inhibited by H2O2, ascorbate and glutathione (GSH). We have estimated the rate constant for the reaction of HOCl with H2O2 to be 1-2 x 10(5) M(-1)s(-1). When compared with authentic HOCl, HOCl-generating systems (Cl- + H2O2 + MPO or chloroperoxidase) were found to be inefficient in damaging DNA. This result most likely arises because the rate constant for reaction of HOCl with H2O2 is about 1000-fold faster than that for the reaction with DNA. HOBr and HOI generating systems also had a limited ability to damage DNA. We conclude that good chlorine accepters and antioxidants protect DNA from hypohalous acid-induced oxidative damage.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS  

Reactions of LEC (Long-Evans rats with a cinnamon-like coat color) rat liver Cu(I)-metallothioneins (MTs) with HgCl2 or K3Fe(CN)(6) were investigated by ESR spectroscopy and generation of hydroxyl radicals was demonstrated using the ESR spin trap, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), When Cu(I)-MTs were incubated with more than one equivalent mole HgCl2 or K3Fe(CN)(6) to Cu+ bound to MTs, strong signals due to Cu2+ appeared, ESR spectra, which were a combination of the DMPO-OH adduct signal and a six-line signal, were observed in the reaction of Cu(I)-MTs with HgCl2, whereas no oxygen radical signal was seen with K3Fe(CN)(6). The DMPO-OH signal intensity was greater in the presence of SOD while the signal disappeared in the presence of catalase, The results suggest that addition of HgCl2 causes the liberation of cuprous ions from MTs followed by a reaction with oxygen, leading to hydroxyl radical formation through a Fenton-type Haber-Weiss reaction. (C) 1997 Academic Press.

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：ZOOLOGICAL SOC JAPAN  

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：ASSOC RESEARCH VISION OPHTHALMOLOGY INC  

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Language：Japanese   Publisher：(公社)日本生化学会  

J-GLOBAL

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

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Language：Japanese  

雑誌掲載版

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Other Link： http://search.jamas.or.jp/link/ui/2001217161

Language：English   Publisher：ELSEVIER SCIENCE BV  

The effect of (-)-(S)-2-[3,5-bis(1,1-dimethylethyl)-4-hyroxyphenyl]-3-[3-[N-methyl-N-[2-(3,4-methylenedioxyphenoxy)-ethyl]amino]propyl]-1,3-thiazolidin-4-one hydrogen fumarate (CP-060S), a novel Ca2+ channel blocker, on hydrogen peroxide (H2O2)- induced cytotoxicity was studied in cultured rat cardiac myocytes. The CP-060S effect was compared with that of CP-060R, an optical isomer of CP-060S with a less potent Ca2+ channel blocking action than CP-060S. H2O2 increased the release of lactate dehydrogenase from cardiac myocytes and decreased the formation of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) (MTT) formazan in cardiac myocytes (i.e., cytotoxic action). Both CP-060S (1 mu M) and CP-060R (1 mu M) attenuated to a similar extent the foregoing alterations induced by H2O2. On the otherhand, 1,3-dimethyl-2-thiourea (10 mM), a scavenger of both H2O2 and hydroxyl radical, also attenuated the H2O2-induced cytotoxicity whereas diltiazem(10 mu M) did not. In an experiment using electron spin resonance (ESR) with 5,5-dimethyl-1-pyrroline N-oxide (DMPO), a spin-trapping agent, both CP-060S and CP-060R decreased the intensity of DMPO-hydroxyl radical signal concentration dependently. These results suggest that CP-060S protects cardiac myocytes from oxidative stress through its radical scavenging action. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0014-2999(99)00708-6

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Language：Japanese   Publisher：(公社)日本生化学会  

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Language：Japanese   Publisher：(公社)日本生化学会  

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Language：Japanese  

CiNii Books

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Language：Japanese  

CiNii Books

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Event date： 2006.6

Language：English   Presentation type：Poster presentation  

Venue：Kyoto, Japan  

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Event date： 2004.4

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto, Japan  

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平成29年8月23日（水）
本学内実験実習機器センター見学

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生化学実習

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生命科学教室への協力

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生命科学教室への協力

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薬理学、生化学

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2003年1回、2008年2回、2009年1回実施

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