• BMB Reports
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• v.33 no.3
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• pp.285-288
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• 2000

Ferricytochrome c was artificially made to receive the aqueous electrons evolved through the influence of illuminated chloroplast. This ferricytochrome c, which was bombarded by electrons, was reduced to ferrocytochrome c by making sure that a certain cytochrome is reduced. This may require an electronic attack that is created by the chloroplast inside the plant cell. The possibility of reversing the oxidation of ferrocytochrome c by cytochrome oxidase was examined using a contrived redox system composed of cytochrome oxidase, ferricytochrome c and chloroplast with illumination. We recognized that the oxidase is unserviceable for the reversibleness in spite of the existence of chloroplast.

• Proceedings of the Korean Biophysical Society Conference
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• 1999.06a
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• pp.46-46
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• 1999

Positively charged cytochrome c interacts with the negatively charged mitochondrial inner membrane. This interaction induces conformational changes in bound cytochrome c. In order to estimate the effect of cytochrome c-membrane interaction on the mitochondrial electron transfer, we have investigated oxidation of ferrocytochrom c in the presence of anionic phospholipids.(omitted)

• Toxicological Research
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• v.4 no.1
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• pp.23-35
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• 1988

The role of calcium in the production of oxygen radical which causes reperfusion damage of ischemic heart has been examined. The reperfusion damage was indrced in isolated Langendorff perfused rat hearts by aortic clamping for 60 min followed by reperfusion with oxygenated Krebs-Henseleit solution with or without 1.25 mM $CaCl_2.$ On reperfusion of the ischemic hearts with the calcium containing solution, the release of cytosolic enzymes (LDH and CPK) increased abruptly. These increased release of enzymes were significantly inhibited by additions of oxygen radical scavengers (SOD, 5,000 U; catalase, 12,500 U) into the reperfusion solution. In the hearts isolated from rats pretreated with allopurinol(20 mg/kg orally, 24 hr and 2 hr prior to the experiments), the levels of enzymes being released during reperfusion were significantly lower than that of the control. However, in the hearts perfused with the calcium-free but oxygenated solution, the increase in the release of cytosolic enzymes during reperfusion was neither inhibited by oxygen radical scavengers nor by allopurinol pretreatment. For providing the evidence of oxygen radical generation during the reperfusion of ischemic hearts in situ, the SOD-inhibitable reduction of exogenously administered ferricytochrome C was measured. In the hearts perfused with the calcium containing solution, the SOD-inhibitable ferricytochrome C reduction increased within the first minute of reperfusion, and was almost completely inhibited by allopurinol pretreatment. When the heart was perfused with the calcium free solution, however, the reduction of ferricytochrome C was not only less than that in the calcium containing condition, but also was not so completely inhibited by allopurinol pretreatment. By ischemia, xanthine oxidase (XOD) in the ventricular tissue was changed qualitatively, but not quantitatively. In the heart made ischemic with the calcium containing condition, the oxygen radical producing O-form of XOD increased, while the D- and D/O-form decreased. However, in the ischemic heart reperfused with the calcium free condition, the D/O-form of XOD was elevated without significant increase in O-form of the enzyme. It is suggested from these results that the calclum may play a contributing role in the genesis of reperfusion damage by promoting the conversion of xanthine oxidase from the D/O-form to the oxygen radical producing O-form in the ischemic myocardium.

• Journal of Chest Surgery
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• v.21 no.5
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• pp.803-815
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• 1988

The present experiments were performed to confirm the hypothesis that xanthine oxidase[XOD], as a source and mechanism of oxygen radical production, plays an important role in the genesis of the reperfusion injury of ischemic myocardium. The experimental ischemic-reperfusion injury was induced in isolated, Langendorff preparations of rat hearts by 60 min. Of global ischemia with aortic clamping followed by 20 min. of reperfusion with oxygenated Krebs-Henseleit solution[pH 7.4, 37*C]. The results were as follows: 1. The releases of creatine phosphokinase and a lipid peroxidation product, malondialdehyde[MDA] into the coronary effluent were abruptly increased upon reperfusion of ischemic hearts. The increases of the enzyme and MDA were suppressed significantly in the hearts removed from rats pretreated with allopurinol, a specific XOD inhibitor[20mg/kg, oral, 24 hrs and 2 hrs before study]. This effect of allopurinol was comparable to that of oxygen radical scavengers, superoxide dismutase[5, 000U] and catalase[12, 500 U]. 2. The increased SOD-inhibitable reduction of ferricytochrome C, which was infused to the hearts starting with reperfusion, was significantly suppressed in allopurinol pretreated hearts. 3. Activities of myocardial XOD were compared in the normal control hearts and the ischemic ones. Total enzyme activities were not different in both hearts. However, comparing with the control, the ischemic ones showed higher activity in 0-form and lower activities in D-form and D/O-form. 4. In the ischemic hearts, phenylmethylsulfonyl fluoride, a serine protease inhibitor, prevented significantly the increase of 0-form and the decreases of D and D/O-form, while thiol reagents did not affect the changes of the enzyme. 5. The increase of 0-form and the decreases of D and D/0-form were not significant in both calcium-free perfused and pimozide, a calmodulin inhibitor, treated ischemic hearts. 6. The SOD-inhibitable reduction of ferricytochrome C were suppressed by PMSF and pimozide treatment as well as by calcium-free perfusion. It is suggested from these results that in the ischemic rat myocardium, xanthine oxidase is converted to oxygen radical producing 0-form by calcium, calmodulin-dependent proteolysis and plays a contributing role in the genesis of ischemic-reperfusion injury by producing oxygen free radicals.

• Bulletin of the Korean Chemical Society
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• v.21 no.4
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• pp.412-418
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• 2000

Association of cytochrome c with anionic membranes involved both electrostatic and hydrophobic interactions and their relative contributions depended on the physical state of the membrane and the redox state of cyto-chromec.Hydrophobic interaction was favored by the membranes in gel phase, by the membranes with a large curvature, and by the membranes with a high surface charge density. Ferrocytochrome c was less dissociable by NaCl than ferricytochrome c suggesting that a lower protein stability is beneficial for hydrophobic interac-tion.Hydrophobic interaction induced larger structural perturbations on cytochrome c as monitored by the loss of the Fe-Met bond and by the increase in the distance between heme and Trp-59. When bound to anionic mem-branes,spin-labeled cytochrome c showed an electron paramagnetic resonance spectrum with two or more components, providing a direct evidence for multiple conformations of bound cytochrome c.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.273-279
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• 1998

The ability of bovine intact red blood cells to scavenge superoxide and hydrogen peroxide by superoxide dismutase, catalase and glutathione peroxidase was investigated. Intact red cells(up to 0.4%) suspensions did not inhibit ferricytochrome c reduction by superoxide in the superoxide generating system. On the other hand, intact red cell(0.4%) suspensions almost completely inhibit ferrocytochrome c oxidation by hydrogen peroxide. The ability of intact red cells to scavenge hydrogen peroxide was mainly attributed to either membrane bound catalase or glutathione peroxidase. The scavenge of hydrogen peroxide by 0.1~0.2% intact red cells showed a trend of dependence on mainly glutathione peroxidase. However, at blood cell concentration higher than 0.3%, the process depended upon peroxidase-independent scavengers like catalase. Enhancement of ferrocytochrome c oxidation by red cells treated with aminotriazole proved that the protection against hydrogen peroxide was due to catalase, while the protection in the presence of glutathione indicated scavenging effect of glutathione peroxidase against hydrogen peroxide.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.345-353
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• 1995

${\beta}-Carboline$ alkaloids including harmaline have been shown to inhibit enzymatically or nonenzymatically induced-lipid peroxidation of microsomes. This study was done to explore the antioxidant ability of harmaline and harmalol on the oxidative injuries of hyaluronic acid, lipid and collagen by $Fe^{2+}$ and $H_2O_2$. Their scavenging actions on reactive oxygen species were also examined. Harmaline, harmalol, superoxide dismutase, catalase and DMSO inhibited both degradation of hyaluronic acid by $Fe^{2+}$ and $H_2O_2$ and lipid peroxidation of microsomes by $Fe^{2+}$. In these reactions, DABCO inhibited degradation of hyaluronic acid but did not affect lipid peroxidation. ${\beta}-Carbolines$ inhibited degradation of cartilage collagen by $Fe^{2+}$, $H_2O_2$ and ascorbic acid. The reduction of ferricytochrome c due to autoxidation of $Fe^{2+}$, which is inhibited by superoxide dismutase, was not affected by harmaline and harmalol. They also did not have a decomposing action on $H_2O_2$. Hydroxyl radical production in the presence of $Fe^{2+}$ and $H_2O_2$ was inhibited by harmaline, harmalol and DMSO. Harmaline and harmalol may inhibit the oxidative injuries of hyaluronic acid, lipid and cartilage collagen by $Fe^{2+}$ and $H_2O_2$ through their scavenging actions on reactive oxygen species, OH and probably iron-oxygen complexes and exert antioxidant abilities.

• Journal of Pharmaceutical Investigation
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• v.22 no.3
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• pp.65-76
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• 1992

The superoxide dismutase (SOD)-mimetic activities of copper complexes of a series of salicylic acid (SA) analogs were tested and compared to the activity of bovine erythrocyte SOD using ferricytochrome c reduction assay. Stability constants of copper complexes were measured potentiometrically using SCOGS2 program. In the presence of 10 g/l albumin, all the copper complexes lost their SOD mimetic activities. Multiple regression analysis was employed for the statistical comparisons between the SOD mimetic activity and their physicochemical properties. Correlation exists for the SOD mimetic activity and steric parameter $(E_s)$ and/or electronic parameter $({\Sigma}{\sigma})$ in xanthine/xanthine oxidase (XOD) system, demonstrating that E, plays a key role in SOD activity whereas ${\Sigma}{\sigma}$ influences it to a lesser extent. The protective effect of copper complexes against membrane damage was measured by counting D-glucose released frm $EG_s$. D-glucose and XOD were entrapped within $EG_s$ and acetaldehyde was used as a substrate for XOD. In this membrane model system using $EG_s$, hydrophobic parameter $({\Sigma}{\pi})$ is of most importance, producing parabolic equation while $E_s$, and ${\Sigma}{\sigma}$ appear to playa minor role in protection against D-glucose release. In summary, to design an efficient SOD mimetic, stability, steric factor, lipophilicity and redox potential should be considered.

• Tuberculosis and Respiratory Diseases
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• v.41 no.1
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• pp.11-19
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• 1994

Background: Mycobacterium tuberculosis is a facultative intracellular pathogen which persists and multiplies within macrophage. Competent cell mediated immunity by cooperation of both T lymphocyte and macrophage of the host is required to kill the Mycobacterium tuberculosis. But a precise understanding of the pathogenesis of tuberculosis infection in pulmonary alveolar macrophage has not been achived. Research on the macrophage's basic microbicidal mechanism has elucidated the importance of oxygen-dependent or oxygen-independent components. Oxygen dependent processing begins with the reduction of oxygen by NADPH oxidase and generation of superoxide. In this study, the oxidative metabolic status of blood monocyte and pulmonary alveolar macrophage in patients with active pulmonary tuberculosis was accessed and compared with that of healthy control subjects to know whether there was a basic difference in superoxide generation by mononuclear cells between two groups. Methods: Pulmonary alveolar macrophage was purified after performing BAL(bronchoalveolar lavage) through the bronchi of infected lesion by plastic adhesion method. Blood monocyte was purified by Ficoll-Hypaque method. Superoxide generation by blood monocyte and pulmonary alveolar macrophage was measured by ferricytochrome-C reduction method after either stimulated with PMA(phorbol myristate acerate) or non-stimulated states. We also measured the effect of pulmonary tuberculosis patient's serum on superoxide generation by monocyte. Results: 1) Generation of superoxide by alveolar macrophage obtained from patients with pulmonary tuberculosis was little higher than those of controls, and PMA enhanced the generation of 2) Generation of superoxide by blood monocyte obtained from patients with pulmonary tuberculosis was little higher than those of control(p>0.05), and PMA more enhanced the generation of superoxide in patientswith pulmonary tuberculosis than those in controls(p<0.02). 3) Patient's serum enhanced the generation of superoxide by blood monocyte obtained from patients with pulmonary tuberculosis and controls, but not in the case of PMA stimulated blood monocyte. Conclusion: The present study suggest that the phenomenon of M.tuberculosis escape the microbicidal action of macrophage was not result of suppressed superoxide generation by blood monocyte and pulmonary alveolar macrophage, rather there might be a factor to stimulate the generation of superoxide by blood monocyte in pulmonary tuberculosis patient serum, but the comparision with effect of control's serum on superoxide generation needs further elucidation.

• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.526-535
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• 1992

Background: The oxygen radicals released by alveolar macrophages contribute to killing of microorganisms including M. tuberculosis. Macrophages are "primrd" for enhanced oxygen radical release by macrophage activator like IFN-$\gamma$ and LPS, which do not themselves cause release of oxygen radicals. Actural production of oxygen radicals is "triggered" by phagocytosis or by exposure to chemical stimuli like PMA or FMLP. There has been debates about the priming effect of alveolar macro phages because they are exposed to usual environmental particles unlike blood monocytes. Therefore we examined priming effect of IFN-$\gamma$ in human alveolar macrophages comparing with that in blood monocytes and rat alveolar macrophages. And we observed the alterations of superoxide production in both human and rat alveolar macrophages after exposure to M. tuberculosis H37Ra bacilli itself and its lysate. Methods: Bronchoalveolar lavage fluid was processed to isolate alveolar macrophages by adherence and the adherent cells were removed by cold shock method. After exposure to M. tuberculosis H37Ra strain, alveolar macrophages were incubated for 24 hours with IFN-$\gamma$. The amount of superoxide production stimulated with PMA was measured by ferricytochrome C reduction method. Results: 1) The priming effect in human alveolar macrophages was not observed even with high concentration of IFN-$\gamma$ while it was observed in blood monocytes and rat alveolar macrophages. 2) Both human and rat alveolar macrophages exposed to avirulent H37Ra strain showed triggering of superoxide release and similar results were shown with the exposure to H37Ra lysate. Conclusion: The priming effect in human alveolar macrophages is not observed because of its usual exposure to environmental particles and avirulent H37Ra strain does not inhibit the activation of alveolar macrophages.