Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of toxic oxygen metabolites (TOM) on the pulmonary vascular bed and airways were studied in isolated, plasma-perfused rat lungs. TOM were generated by xanthine oxidase (XO) (0.1 or 0.25 unit.ml-1) and hypoxanthine (HX) (1 mol.l-1). In vitro measurements by chemiluminescence indicated that the major oxygen metabolite generated by XO and HX was H2O2. Measurements of PO2 in the perfusate as an indicator of O2-consumption suggested that production of TOM by XO and HX was finished within 30 min. XO and HX induced an early dose-dependent bronchoconstriction and a late increase in transpulmonary pressure (Ptp). Pulmonary arterial pressure (Ppa) increased gradually and levelled off within 30 min with low-dose XO, but not with high-dose XO. As judged by weight increase of the lungs, interstitial edema occurred regularly. Allopurinol, an inhibitor of XO, blocked the lung responses caused by XO and HX. Catalase attenuated all lung responses induced by XO and HX, while superoxide dismutase had no effect. The hydroxyl radical scavenger dimethylsulfoxide abolished the increase in Ptp and attenuated the increase in Ppa, but did not consistently protect the lungs from edema development. This study shows that TOM induce vasoconstriction, bronchoconstriction and lung edema in plasma-perfused rat lungs, mainly due to generation of H2O2 and the hydroxyl radical.
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PMID:Toxic oxygen metabolites induce vasoconstriction and bronchoconstriction in isolated, plasma-perfused rat lungs. 200 2

The effectiveness of 24-hour hypothermic machine perfusion with TP-V (a hyperosmolar colloid solution containing dextrose, sucrose and ATP-MgCl2) alone, or in combination with oxygen free radical scavengers, was evaluated in isolated-perfused canine heart-lungs. Heart-lungs were perfused at 4 degrees C in either TP-V (n = 6), TP-V/Allopurinol (500 mg/L) (n = 6), or TP-V/Allopurinol (500 mg/L) & Catalase (5000 U/L) (n = 5). Lung inflation was maintained with 100% nitrogen. Following preservation, the heart-lungs were perfused with an albumin-mannitol perfusate for 3 hours at 37 degrees C, for functional, hemodynamic, and laboratory determinations. Cold preservation with TP-V/Allopurinol, and TP-V/Allopurinol & Catalase resulted in physiologically normal LDH levels during the 3-hour normothermic isolated perfusion test period. Significantly lower enzyme activity for CPK was evident at 0 (p less than .005) and 3 hours (p less than .05) of perfusion, while no significant differences in lactate production were seen among the groups. In addition, pH, PCO2, PO2, and left ventricular, aortic, and coronary artery pressures all remained within normal physiologic range, with no significant differences seen among the three groups. 99m Technetium scans demonstrated adequate patency among the heart-lungs, with better flow seen in those perfused with TP-V/Allopurinol & Catalase. Histological specimens confirmed a decrease in myocardial and pulmonary damage when Allopurinol and/or Catalase was used. It appears that oxygen free radical scavengers provide some protection from canine heart-lungs which have been hypothermically preserved for 24 hours.
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PMID:Effect of 24-hour preservation with oxygen free radical scavengers on isolated-perfused canine heart-lungs. 302 18

The oxygen paradox refers to the abrupt release of cytoplasmic enzymes and severe cellular disruption that occurs following reoxygenation of anoxic perfused hearts. In this study, the ability of a series of oxygen-derived free radical inhibitors and scavenging agents to protect isolated perfused rat hearts from the oxygen-induced enzyme release following 30 or 60 mins of anoxic perfusion (oxygen paradox) and cumene hydroperoxide-induced injury was evaluated. Malondialdehyde (MDA) release, an indicator of lipid peroxidation, and creatine kinase (CK) release, an indicator of cellular injury, were monitored. We evaluated five agents previously reported to scavenge or inhibit the formation of oxygen free radicals. The putative hydroxyl radical scavengers dimethylthiourea (DMTU) and mannitol; catalase, an agent protective against peroxide injury; allopurinol, an inhibitor of xanthine oxidase; and albumin, a non-specific protein control, were evaluated. Coronary flow rates and myocardial temperature were continuously monitored to ensure uniform perfusion conditions. The MDA assay was carefully monitored by constructing standard curves on each experimental day. Addition of 20 microM cumene hydroperoxide to oxygenated perfused hearts caused peroxidative cell injury as evidenced by significant MDA and CK release in the coronary effluent. DMTU and catalase provided near complete protection from cumene hydroperoxide-induced cell injury but did not reduce CK release from hearts subjected to either the mild (30-min) or the severe (60-min) oxygen paradox (reoxygenation-induced injury). Allopurinol caused a significant reduction in MDA release but not CK release from oxygen paradox-injured hearts. Allopurinol and albumin had no significant effect on MDA release from cumene-hydroperoxide-injured hearts. Catalase (300 U/ml) caused a mild but not statistically significant reduction in MDA release from cumene hydroperoxide injury but did not provide protection from the oxygen paradox at either injury level. Mannitol (120 mM), in contrast to DMTU, was ineffective in reducing cumene-induced injury but showed a significant protective effect against oxygen paradox-induced damage. It is concluded that the ability of mannitol to reduce reoxygenation-induced CK release in the oxygen paradox may be due to its osmotic activity and consequent ability to prevent cellular swelling rather than its activity as an oxygen-free radical scavenger.
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PMID:Effects of the free radical scavenger DMTU and mannitol on the oxygen paradox in perfused rat hearts. 311 97

Copper Fenton systems (Cu(II)/H2O2 and Cu(II)/Asc) inactivated the lipoamide reductase and enhanced the diaphorase activity of pig-heart lipoamide dehydrogenase (LADH). Cupric ions alone were less effective. As a result of Cu(II)/H2O2 treatment, the number of titrated thiols in LADH decreased from 6 to 1 per subunit. NADH and ADP (not NAD+ or ATP) enhanced LADH inactivation by Cu(II). NADH also enhanced the effect of Cu(II)/H2O2. Dihydrolipoamide, dihydrolipoic acid, Captopril, acetylcysteine, EDTA, DETAPAC, histidine, bathocuproine, GSSG and trypanothione prevented LADH inactivation. 100 microM GSH, DL-dithiothreitol, N-(2-mercaptopropionylglicine) and penicillamine protected LADH against Cu(II)/Asc and Cu(II), whereas 1.0 mm GSH and DL-dithiothreitol also protected LADH against Cu(II)/H2O2. Allopurinol provided partial protection against Cu(II)/H2O2. Ethanol, mannitol, Na benzoate and superoxide dismutase failed to prevent LADH inactivation by Cu(II)/H2O2 or Cu(II). Catalase (native or denaturated) and bovine serum albumin protected LADH but that protection should be due to Cu binding. LADH inhibited deoxyribose oxidation and benzoate hydroxylation by Cu(II)/H2O2. It is concluded that site-specifically generated HO, radicals were responsible for LADH inactivation by Cu(II) Fenton systems. The latter effect is discussed in the context of ischemia-reoxygenation myocardial injury.
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PMID:Inactivation of heart dihydrolipoamide dehydrogenase by copper Fenton systems. Effect of thiol compounds and metal chelators. 775

One of the objectives of studying endothelial cells in vitro is to evaluate neutrophil-endothelial cell interactions including potential consequences of oxidant-mediated damage to the endothelial cell. Current understanding of endothelial cell oxidative function is derived primarily from the measurement of extracellular products. We utilized 2 dyes, 2',7'-dichlorofluorescein diacetate (DCFH-DA) and hydroethidine (HE), which measure hydrogen peroxide (H2O2) and superoxide anion (O2-) respectively, for their suitability to monitor oxidative mechanisms in endothelial cells and to provide a reliable measure of intracellular oxidants. Endothelial cells stained with DCFH-DA and stimulated with H2O2 exhibited an increase in the fluorescent product 2',7'-dichlorofluorescein (DCF) (measure of intracellular H2O2) which peaked at 10 min. Endothelial cells stained with HE and stimulated with H2O2 exhibited an increase in the fluorescent product ethidium bromide (EB) (measure of intracellular O2-) which lasted for approximately 60 min. Superoxide dismutase increased DCF fluorescence in endothelial cells stimulated with H2O2 by 158%. Allopurinol (xanthine oxidase inhibitor) reduced DCF and EB fluorescence by 48% and 37% respectively in endothelial cells stimulated with H2O2. Catalase completely inhibited an increase in DCF or EB fluorescence in endothelial cells stimulated with H2O2. There was a direct correlation between mean DCF and EB fluorescence intensity and the concentration of H2O2 or the number of phorbol 12-myristate 13-acetate-activated neutrophils added to endothelial cells. We conclude from these studies that DCFH-DA and HE can be used to measure intracellular H2O2 and O2- in endothelial cells and that the xanthine oxidase pathway for intracellular O2- production accounts for approximately 40% of the total intracellular O2- generated in endothelial cells after stimulation with H2O2. The combination of image cytometry and flow cytometry will be important for future evaluations of endothelial cell function.
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PMID:Intracellular hydrogen peroxide and superoxide anion detection in endothelial cells. 830 Dec 22

Abnormal hemostatic profiles indicating hemorrhagic tendency have been reported in rodents exposed to prolonged fluctuation in ambient temperature, known as SART (specific alternation of rhythm in temperature)-stressed animals. In this study, investigation was made of possible involvement of oxygen-derived free radicals in the development of stress-induced hemostatic alteration. SART-stressed rats and mice exhibited marked decrease in platelet count, fibrinogen level and factor VIII:C activity. Superoxide dismutase, when administered s.c. twice a day to mice for 7 days of stress exposure, inhibited the above alterations. Catalase given in the same manner, had essentially the same effect, though to a lesser extent. Allopurinol administered orally once daily during stress reduced stress-induced thrombocytopenia, but caused considerable increase in fibrinogen and factor VIII:C activity in stressed and unstressed mice. Lipid peroxide significantly increased in the heart but not in the plasma following stress exposure in rats and mice. Active oxygens would thus appear to be, at least partially, involved in the development of abnormal hemostasis induced by SART stress.
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PMID:Possible involvement of oxygen-derived free radicals in abnormal hemostasis induced by SART stress (repeated cold stress) in laboratory animals. 830 72

A simple method in mice was established to screen anti-ischemic compounds. Thirteen times binding of rubber ring (1 x 1 mm, d = 42 mm) for 4.5 hrs, swelled the paws of 60% mice applied and 14 times binding swelled only of 5% mice. Critically reversible limit lay between these conditions. "All or none" rule dominated the paw swelling perhaps due to different endogenous anti-oxidants' levels of individual mice. Determination of paw reversibility at 90 min of recirculation, was proved to be suitable. Swollen paws at this time returned normal and the paws with no-reflow dropped out by muscle necrosis after several days. Intravenous (i.v.) bovine Cu, Zn-SOD and bacterial Mn-SOD (3-10 x 10(4) U/kg) or liposomal Cu, Zn-SOD (0.3-3 x 10(4) U/kg) were protective (35-50%) by 14 times binding. Allopurinol (10-100 mg/kg) and D-mannitol (3-30 mg/kg) was effective (25-55%). Catalase (i.v., up to 10(5) U/kg) showed little protection, but local injection of 100 U/kg resulted in 50% protection. Glutathione (30 mg/kg) was suppressive only by local injection suggesting the importance of administration route. Desferal, heparin and nitric oxide synthesis inhibitor showed some protection, but indomethacin, mepyramine, ascorbate, vitamin E and dexamethasone were without effect. Excess dosing of all anti-oxidants tested, dramatically decreased their effects demanding caution for therapeutic trials.
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PMID:Superoxide dismutases and anti-oxidants protected mice from no-reflow and necrotic damage induced by ischemia. 831 25