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)

The production of H2O2 by cells in cold paraformaldehyde-fixed frozen sections of inflammatory lesions was histochemically demonstrated by incubating them with diaminobenzidine (DAB) for 2 to 6 h. Catalase (150 micrograms/ml, about 1400 U/ml) inhibited the reaction, indicating that H2O2 was required to produce the chromogenic DAB product. Granulocytes (PMNs and eosinophils) were the main types of cells stained by the DAB reaction. Positive staining of macrophages was less frequent. The H2O2 was produced by metabolic enzymes that were still active after cell death and mild fixation. An atmosphere of 95 to 100% oxygen enhanced the specific DAB reaction, and an atmosphere of 100% nitrogen eliminated it. The DAB histochemical reaction to detect H2O2 requires the presence of peroxidases to produce the colored reaction product. Within our tissue sections, such peroxidases were evidently present in excess, because addition of low concentrations of H2O2 significantly increased the reaction product. Although some of the H2O2 produced by the granulocytes may have been derived from the dismutation of superoxide (O2-), the NADPH oxidase pathway for O2- formation did not seem to be involved: NADPH oxidase, a rather labile enzyme, should not be active after mild fixation, and diphenyleneiodonium (100 microM), an inhibitor of flavine-requiring NADPH oxidase, did not inhibit the reaction. Reactive nitrogen intermediates were also not involved, because NG-monomethyl-L-arginine and NG-nitro-L-arginine methyl ester, inhibitors of nitric oxide synthetase, did not appreciably inhibit the reaction. We conclude that stable, non-flavine-requiring oxidases, possibly cyclooxygenases or lipoxygenases, produced the H2O2 measured histochemically by our DAB reaction. These studies were made on tissue sections of acute dermal inflammatory lesions produced in rabbits by the topical application of 1% sulfur mustard [bis(2-chloroethyl) sulfide] in methylene chloride. Both intact PMNs and disintegrating PMNs in the base of the crust produced H2O2. Despite the production of H2O2 and the presence of peroxidase activity, no tissue damage was seen microscopically near the H2O2-producing cells, which indicates that the tissues are well protected by the antioxidants present in this self-limiting inflammatory reaction.
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PMID:Histochemical demonstration of hydrogen peroxide production by leukocytes in fixed-frozen tissue sections of inflammatory lesions. 793 Sep 39

1. Small arteries were isolated from either rat mesentery or human subcutaneous fat, and mounted in a myograph for the measurement of isometric force. 2. Superoxide dismutase, either in the presence or absence of catalase, relaxed noradrenaline-induced tone. This effect was abolished by removal of the endothelium or incubation with an inhibitor of NO synthase, N-omega-nitro-L-arginine methyl ester. Catalase alone had a negligible effect on noradrenaline-induced tone. 3. Captopril, an angiotensin-converting enzyme inhibitor and putative free-radical scavenger, did not relax pre-contracted isolated vessels. N-Acetylcysteine caused an endothelium-independent relaxation of rat vessels. Similar effects were observed in human vessels. 4. Acetylcholine induced a concentration-dependent relaxation of isolated resistance arteries, which was inhibited by removal of the endothelium or N-omega-nitro-L-arginine methyl ester, but unaffected by indomethacin. Preincubation with captopril, N-acetylcysteine or catalase alone did not alter the acetylcholine concentration-response relationship, but superoxide dismutase in combination with catalase enhanced responses to acetylcholine, causing a six-fold increase in potency. 5. Superoxide dismutase causes endothelium-dependent relaxation of resistance arteries and potentiates responses to acetylcholine. This action is probably due to the ability of the enzyme to scavenge superoxide anions which inhibit endothelium-dependent relaxation. 6. N-Acetylcysteine causes an endothelium-independent relaxation of resistance arteries which is probably unrelated to the putative ability of this compound to scavenge superoxide radicals and may reflect a direct action on vascular smooth muscle.
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PMID:Free-radical scavengers, thiol-containing reagents and endothelium-dependent relaxation in isolated rat and human resistance arteries. 838 51

The influence of nitric oxide on human sperm hyperactivation and capacitation, as well as its mechanism of action and its possible origin from spermatozoa were studied. Percoll-washed spermatozoa from healthy volunteers were incubated in Ham's F-10 medium supplemented or not with the nitric oxide-releasing agents, diethylamine-NONOate or spermine-NONOate, in combination or not with superoxide dismutase or catalase (scavengers for the superoxide anion and for hydrogen peroxide, respectively), or with sodium nitrate, sodium nitrite, or preincubated NONOates. Sperm hyperactivation, capacitation, and nitric oxide synthase activity were determined. High concentrations (0.3 to 1 mM) of NONOates reduced sperm motility. However, a lower concentration (0.1 mM) of the two NONOates had no effect on the percentage of sperm motility or of hyperactivation but resulted in a significant increase in sperm capacitation (24% +/- 4%) when compared to that of control spermatozoa (Ham's F-10 alone, 12% +/- 2%). Nitric oxide released by the NONOates appeared responsible for this effect because sodium nitrate or nitrite or preincubated NONOates (to exhaust the formation of nitric oxide) had no influence on sperm capacitation. Catalase, but not superoxide dismutase, abolished the capacitating action of the NONOates. No nitric oxide synthase activity was detected in spermatozoa, whether they were in their basal state or already capacitated. Furthermore, the nitric oxide synthetase inhibitor L-NG nitroarginine methyl ester did not block sperm capacitation induced by fetal cord serum ultrafiltrate. It is therefore concluded that, although spermatozoa do not possess detectable nitric oxide synthase activity, low levels of nitric oxide induce human sperm capacitation, and this action likely involves hydrogen peroxide.
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PMID:Low levels of nitric oxide promote human sperm capacitation in vitro. 857 82

The role of hydrogen peroxide in the induction of cell death in human promyelocytic leukemic HL-60 cells by sodium 5,6-benzylidene-L-ascorbate (SBA) and its degradation product, ascorbic acid, was investigated. Millimolar concentrations of these compounds induced cell death, characterized by cell shrinkage, nuclear and internucleosomal DNA fragmentation, disappearance of microvilli and condensation of chromatin near the nuclear membrane. Catalase significantly reduced the cytotoxic activity of these compounds, whereas superoxide dismutase, nitric oxide (NO) generator, NO scavenger and NO synthase inhibitor were inactive, suggesting the possible role of H2O2. Determination of H2O2 with the peroxyoxalate chemiluminescence demonstrated that sodium ascorbate and SBA produced H2O2 in amounts necessary for cell death induction.
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PMID:Role of hydrogen peroxide for cell death induction by sodium 5,6-benzylidene-L-ascorbate. 967 92

Cigarette smoking is associated with impaired endothelium-dependent vasodilation and reduced nitric oxide (NO) in the exhaled air of smokers. To explore the mechanism for the impairment of NO-mediated vasodilation, we studied the effect of cigarette smoke extract (CSE) on NO synthase (eNOS) activity and content in pulmonary artery endothelial cells (PAEC). Incubation of PAEC with CSE resulted in a time- and dose-dependent decrease in eNOS activity. The inhibitory effect of CSE on eNOS activity was not reversible. Both gas-phase and particulate-phase extracts of CSE contributed to the inhibition of eNOS activity. The protein kinase c (PKC) inhibitors staurosporine and chelerythrine did not affect the CSE-induced inhibition of eNOS activity. Catalase, superoxide dismutase (SOD), vitamin C, vitamin E, glutathione, and dithiothreitol (DTT) also did not prevent the CSE-induced inhibition of eNOS activity, and incubation of PAEC with 3 mM nicotine did not change the activity of eNOS. Treatment of PAEC with CSE also caused a nonreversible, time-dependent decrease in eNOS protein content detected by Western blot analysis, and in eNOS messenger RNA (mRNA) detected by Northern blot analysis. Treatment of PAEC with CSE had no effect on cell protein or glutathione contents or on lactate dehydrogenase (LDH) release. These results indicate that exposure to CSE causes an irreversible inhibition of eNOS activity in PAEC, and suggest that the decreased activity is secondary to reduced eNOS protein mass and mRNA. The decrease in eNOS activity may contribute to the high risk of pulmonary and cardiovascular disease in cigarette smokers.
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PMID:Effect of cigarette smoke extract on nitric oxide synthase in pulmonary artery endothelial cells. 980 47

Our objective is to clarify the role of reactive oxygen species (ROS) in the atrophying tail of anuran tadpoles (tail apoptosis). Changes in catalase, superoxide dismutase (SOD) and caspase activity, genomic DNA, and nitric oxide (NO) generation were investigated biochemically using Rana japonica tadpole tails undergoing regression during thyroid hormone enhancement. DNA fragmentation and ladder formation with concomitant shortening of tadpole tail were induced by DL-thyroxine (T4) in culture medium. Catalase activity was also decreased by T4 treatment. T4 was also found to increase NO synthase (NOS) activity in cultured tadpole tail with concomitant increase in the concentration of NO2- plus NO3- (NOx) in the culture medium. Additional treatment with N-monomethyl-L-arginine (NMMA), a potent inhibitor of NOS, suppressed the enhancing effects of T4 on tail shortening and catalase activity reduction. It was also found that treatment with isosorbide dinitrate (ISDN), a NO generating drug, alone also had an enhancing effect on tail shortening and catalase activity reduction similar to that seen with T4. Both NO and an NO donor (ISDN) strongly suppressed catalase activity. Kinetic analysis revealed that catalase activity decreased and caspase-3-like activity increased during normal tadpole tail atrophy (apoptosis). These results suggested that T4 enhances NO generation, thereby strongly inhibiting catalase activity, resulting in an increase in hydrogen peroxide, and that the oxidative stress elicited by excess hydrogen peroxide might activate cysteine-dependent aspartate-directed protease-3 (caspase-3-like protease), which is thought to cause DNA fragmentation, leading to apoptosis.
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PMID:Thyroxine enhancement and the role of reactive oxygen species in tadpole tail apoptosis. 1023 45

The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several endothelium-derived relaxing factors, such as prostacyclin, nitric oxide (NO), and the previously unidentified endothelium-derived hyperpolarizing factor (EDHF). In this study, we examined our hypothesis that hydrogen peroxide (H(2)O(2)) derived from endothelial NO synthase (eNOS) is an EDHF. EDHF-mediated relaxation and hyperpolarization in response to acetylcholine (ACh) were markedly attenuated in small mesenteric arteries from eNOS knockout (eNOS-KO) mice. In the eNOS-KO mice, vasodilating and hyperpolarizing responses of vascular smooth muscle per se were fairly well preserved, as was the increase in intracellular calcium in endothelial cells in response to ACh. Antihypertensive treatment with hydralazine failed to improve the EDHF-mediated relaxation. Catalase, which dismutates H(2)O(2) to form water and oxygen, inhibited EDHF-mediated relaxation and hyperpolarization, but it did not affect endothelium-independent relaxation following treatment with the K(+) channel opener levcromakalim. Exogenous H(2)O(2) elicited similar relaxation and hyperpolarization in endothelium-stripped arteries. Finally, laser confocal microscopic examination with peroxide-sensitive fluorescence dye demonstrated that the endothelium produced H(2)O(2) upon stimulation by ACh and that the H(2)O(2) production was markedly reduced in eNOS-KO mice. These results indicate that H(2)O(2) is an EDHF in mouse small mesenteric arteries and that eNOS is a major source of the reactive oxygen species.
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PMID:Hydrogen peroxide is an endothelium-derived hyperpolarizing factor in mice. 1113 74

Two distinct systems of different origin are involved in the pathogenesis of both infectious and immunological vasculitis syndrome: nitric oxide (NO) from endothelial cells and granulocyte NADPH oxidase. In this study, in 31 children with immune system dysfunction, NO, NO synthase (NOS) and antioxidant enzyme activities [catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx)], as well as immunological parameters, were investigated. On the basis of the clinical findings, all children were divided into three groups: group I, 8 children clinically showing macular skin manifestations; group II, 11 children with maculo-papulous changes; and group III, 12 children with clinical findings of papulous changes. Plasma NO values in groups II and III were significantly elevated (79.14+/-30.13 and 65.32+/-6.70 micromol/l), compared to the control group (41.24+/-3.65 micromol/l), while group I showed statistically lower values (32.38+/-3.37 micromol/l). In children with the highest level of NO (group II) NOS activity was two-fold higher (1.77+/-0.59 nmol/ml/min; p<0.01) than in controls (0.98+/-0.23 nmol/ml/min). Catalase activity showed a significant increase and SOD activity a significant decrease in all experimental groups, while GPx was not significantly changed. The results show that immune system dysfunction manifested as vasculitis is associated with significant disturbances in the NO system and free radicals scavengers.
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PMID:Immune system-mediated endothelial damage is associated with NO and antioxidant system disorders. 1555 69

Diaphorase was studied as a possible oxidoreductase participating in NO production from some vasorelaxants. In the presence of NADH or NADPH, diaphorase can convert selected NO donors, glycerol trinitrate (GTN) and formaldoxime (FAL) to nitrites and nitrates with NO as an intermediate. This activity of diaphorase was inhibited by diphenyleneiodonium (DPI) (inhibitor of some NADPH-dependent flavoprotein oxidoreductases), while it remained uninhibited by NG-nitro-L-arginine methyl ester (inhibitor of NO synthase) 7-Ethoxyresorufin (inhibitor of cytochrome P-450 1A1 and cytochrome P-450 NADPH-dependent reductase) inhibited the conversion of GTN only. Existence of NO as an intermediate of the reaction was supported by results of electron paramagnetic resonance spectroscopy. In addition to its ability to affect the above mentioned NO donors, diaphorase was able to reduce 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) and thus to eliminate its NO scavenging effect. This activity of diaphorase could also be inhibited by DPI. The reaction of diaphorase with GTN and PTIO was not affected by superoxide dismutase (SOD) or catalase. Reaction of FAL with diaphorase was lowered with SOD by 38 % indicating the partial participation of superoxide anion probably generated by the reaction of diaphorase with NADH or NADPH. Catalase had no effect. Diaphorase could apparently be one of the enzymes participating in the metabolism of studied NO donors to NO. The easy reduction and consequent elimination of PTIO by diaphorase could affect its use as an NO scavenger in biological tissues.
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PMID:Diaphorase can metabolize some vasorelaxants to NO and eliminate NO scavenging effect of 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). 1558 29

Reactive oxygen species (ROS) and nitric oxide (NO) have a role in the development of pulmonary fibrosis after bleomycin administration. The ROS production induces an antioxidant response, involving superoxide dismutases (SODs), catalase, and glutathione peroxidases. We compared in situ oxidative burden and antioxidant enzyme activity in bleomycin-injured rat lungs and normal controls. ROS expression and catalase, glucose-6-phosphate-dehydrogenase (G6PHD), and NOS/NADPH-diaphorase activity were investigated by using histochemical reactions. Nitric oxide synthase (e-NOS and i-NOS) and SOD (MnSOD, Cu/ZnSOD, ECSOD) expression was investigated immunohistochemically. After treatment ROS production was enhanced in both phagocytes and in type II alveolar epithelial cells. Mn, Cu/Zn, and ECSOD were overexpressed in parenchymal cells, whereas interstitium expressed ECSOD. Catalase and G6PHD activity was moderately increased in parenchymal and inflammatory cells. NOS/NADPH-d activity and i-NOS expression increased in alveolar and bronchiolar epithelia and in inflammatory cells. It can be suggested that the concomitant activation of antioxidant enzymes is not adequate to scavenge the oxidant burden induced by bleomycin lung damage. Inflammatory cells and also epithelial cells are responsible of ROS and NO production. This oxidative and nitrosative stress may be a substantial trigger in TGF-beta1 overexpression by activated type II pneumocytes, leading to fibrotic lesions.
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PMID:In situ assessment of oxidant and nitrogenic stress in bleomycin pulmonary fibrosis. 1630 78


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