Optical measurement of the catalase-hydrogen peroxide intermediate (Compound I) in the liver of anaesthetized rats and its implication to hydrogen peroxide production in situ

The spectrophotometric determination of the catalase-H2O2 intermediate (Compound I) was extended to the liver in situ in anaesthetized rats. The rate of H2O2 production was determined for the liver in situ with endogenous substrates, and in the presence of excess of glycollate. Glycollate infusion doubled H2O2 production rate in the liver of air-breathing rats, and caused a fourfold increase when rats breathed O2 at 1 times 10(5) Pa. Hyperbaric O2 up to 6 times 10(5) Pa did not increase H2O2 generation supported by endogenous substrates, nor did it increase H2O2 production above that produced by 1 times 10(5) Pa O2 in glycollate-supplemented rats. The rates of ethanol oxidation via hepatic catalase and via alcohol dehydrogenase in the whole body were separately measured. The contribution of hepatic catalase to ethanol oxidation was found to be approx. 10 percent in endogenous conditions and increased to 30 percent or more of the total ethanol oxidation in rats supplemented with glycolate.

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Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide

Molecules ◽

10.3390/molecules26133844 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3844

Author(s):

Lijuan Li ◽

Bingdong Li ◽

Liwei Feng ◽

Xiaoqiu Zhang ◽

Yuqian Zhang ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Reaction System ◽

Reaction Medium ◽

Pure Tio2 ◽

H2o2 Production ◽

Tio2 Photocatalyst ◽

H2o2 Decomposition ◽

Spin Resonance ◽

Photocatalytic Synthesis

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F− modification inhibits the H2O2 decomposition through the formation of the ≡Ti–F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F− modification and without F− modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

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Hyperoxia increases H2O2 production by brain in vivo

Journal of Applied Physiology ◽

10.1152/jappl.1987.63.1.353 ◽

1987 ◽

Vol 63 (1) ◽

pp. 353-358 ◽

Cited By ~ 121

Author(s):

T. Yusa ◽

J. S. Beckman ◽

J. D. Crapo ◽

B. A. Freeman

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Catalase Activity ◽

Intermediate Compound ◽

H2o2 Production ◽

H2o2 Concentration ◽

Compound I ◽

Central Nervous System Toxicity ◽

Competitive Substrate

Hyperoxia and hyperbaric hyperoxia increased the rate of cerebral hydrogen peroxide (H2O2) production in unanesthetized rats in vivo, as measured by the H2O2-mediated inactivation of endogenous catalase activity following injection of 3-amino-1,2,4-triazole. Brain catalase activity in rats breathing air (0.2 ATA O2) decreased to 75, 61, and 40% of controls due to endogenous H2O2 production at 30, 60, and 120 min, respectively, after intraperitoneal injection of 3-amino-1,2,4-triazole. The rate of catalase inactivation increased linearly in rats exposed to 0.6 ATA O2 (3 ATA air), 1.0 ATA O2 (normobaric 100% O2) and 3.0 ATA O2 (3 ATA 100% O2) compared with 0.2 ATA O2 (room air). Catalase inactivation was prevented by pretreatment of rats with ethanol (4 g/kg), a competitive substrate for the reactive catalase-H2O2 intermediate, compound I. This confirmed that catalase inactivation by 3-amino-1,2,4-triazole was due to formation of the catalase-H2O2 intermediate, compound I. The linear rate of catalase inactivation allows estimates of the average steady-state H2O2 concentration within brain peroxisomes to be calculated from the formula: [H2O2] = 6.6 pM + 5.6 ATA-1 X pM X [O2], where [O2] is the concentration of oxygen in ATA that the rats are breathing. Thus the H2O2 concentration in brains of rats exposed to room air is calculated to be about 7.7 pM, rises 60% when O2 tension is increased to 100% O2, and increases 300% at 3 ATA 100% O2, where symptoms of central nervous system toxicity first become apparent. These studies support the concept that H2O2 is an important mediator of O2-induced injury to the central nervous system.

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Oxidation of 4-tert-Butylcatechol and Dopamine by Hydrogen Peroxide Catalysed by Horseradisch Peroxidase

Biological Chemistry ◽

10.1515/bc.1999.085 ◽

1999 ◽

Vol 380 (6) ◽

Cited By ~ 8

Author(s):

M. García-Moreno ◽

M. Moreno-Conesa ◽

J.N. Rodríguez-López ◽

F. García-Cánovas ◽

R. Varón

Keyword(s):

Hydrogen Peroxide ◽

Electron Transfer ◽

Horseradish Peroxidase ◽

Resting State ◽

Intermediate Compound ◽

Transfer Reactions ◽

Single Electron Transfer ◽

Compound I ◽

Compound Ii ◽

Enzyme Intermediate

AbstractThe catalytic cycle of horseradish peroxidase (HRP; donor:hydrogen peroxide oxidoreductase; EC 1.11.1.7) is initiated by a rapid oxidation of it by hydrogen peroxide to give an enzyme intermediate, compound I, which reverts to the resting state via two successive single electron transfer reactions from reducing substrate molecules, the first yielding a second enzyme intermediate, compound II. To investigate the mechanism of action of horseradish peroxidase on catechol substrates we have studied the oxidation of both 4-

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Enhanced in vivo H2O2 generation by rat kidney in glycerol-induced renal failure

AJP Renal Physiology ◽

10.1152/ajprenal.1989.257.3.f440 ◽

1989 ◽

Vol 257 (3) ◽

pp. F440-F445 ◽

Cited By ~ 5

Author(s):

B. Guidet ◽

S. V. Shah

Keyword(s):

Hydrogen Peroxide ◽

Renal Failure ◽

Acute Renal Failure ◽

Catalase Activity ◽

Tissue Injury ◽

Rat Kidney ◽

Intermediate Compound ◽

Treated Group ◽

Compound I

Aminotriazole-mediated inhibition of catalase has been used in previous studies as a measure of in vivo changes in the hydrogen peroxide generation. Using this method, we found a significantly higher inhibition of renal catalase activity at various time points (30, 60, and 90 min) in glycerol-treated rats (a well-established model for myoglobinuric acute renal failure) compared with rats treated with aminotriazole alone. The greater inhibition in the glycerol-treated group was not due to differences in aminotriazole levels. We confirmed that catalase inactivation by aminotriazole was due to formation of catalase-hydrogen peroxide intermediate (compound I) because catalase inactivation was prevented by ethanol, a competitive substrate for compound I. There were no significant differences in the aminotriazole-induced inhibition of renal cortical catalase activity in control and uranyl nitrate-treated rats, suggesting that there was no enhanced generation of hydrogen peroxide in this model of acute renal failure. Taken together, these data provide evidence for enhanced generation of hydrogen peroxide in glycerol-induced acute renal failure and suggest that the enhanced generation of hydrogen peroxide in the glycerol-induced acute renal failure is not a result of nonspecific response to tissue injury.

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Electro-generation of hydrogen peroxide for electro-Fenton: Application in Glyphosate herbicide treatment

VNU Journal of Science Earth and Environmental Sciences ◽

10.25073/2588-1094/vnuees.4074 ◽

2017 ◽

Vol 33 (4) ◽

Author(s):

Thanh Son Le ◽

Tran Manh Hai ◽

Doan Tuan Linh

Keyword(s):

Hydrogen Peroxide ◽

Ph Value ◽

Current Intensity ◽

H2o2 Production ◽

Aquatic Life ◽

Herbicide Treatment ◽

Initial Ph ◽

Glyphosate Herbicide ◽

Save Energy

One of the major and serious pollution issues in an agriculture-based country as Vietnam is derived from herbicide, especially Glyphosate herbicide which can cause a massive quantity of adverse effects and acute toxicity to aquatic life and human health. Hence, this research focused on setting up an electro-Fenton system with a Pt gauze anode and a commercial carbon felt cathode for Glyphosate herbicide treatment with the primary mechanism based on the in situ hydrogen peroxide electro-generation and ferrous ion catalyst regeneration. This study investigated effect of initial pH and current intensity on both the amount of hydrogen peroxide production and the Glyphosate mineralization performance. The results indicated that the pH value was 3, the quantity of H2O2 production on cathode reached largest, then the Glyphosate mineralization performance was optimum, approximately 0.15 mg/L and 60% at 50 electrolysis time respectively. Moreover, when current intensity increased, the amount of H2O2 electro-generation increased, leading to better Glyphosate mineralization efficiency. Nonetheless, in order to minimize the electrode corrosion as well as save energy cost, the optimum current intensity was found being 0.5 A.

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Primary sludge to valuable chemicals, hydrogen peroxide (H2O2), in microbial electrochemical cells - H2O2 production and in-situ sludge treatment

Proceedings of the Water Environment Federation ◽

10.2175/193864718824829028 ◽

2018 ◽

Vol 2018 (4) ◽

pp. 482-495

Author(s):

Dongwon Ki ◽

Rick Kupferer ◽

César I Torres

Keyword(s):

Hydrogen Peroxide ◽

H2o2 Production ◽

Electrochemical Cells ◽

Sludge Treatment ◽

Primary Sludge

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Biogeochemical Alteration of an Aquifer Soil during In Situ Chemical Oxidation by Hydrogen Peroxide and Peroxymonosulfate

Environmental Science & Technology ◽

10.1021/acs.est.0c06206 ◽

2021 ◽

Author(s):

Eun-Ju Kim ◽

Saerom Park ◽

Sawaira Adil ◽

Seunghak Lee ◽

Kyungjin Cho

Keyword(s):

Hydrogen Peroxide ◽

Chemical Oxidation ◽

In Situ Chemical Oxidation ◽

Oxidation By Hydrogen Peroxide

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Radioiodine in Differentiated Thyroid Carcinoma: Do We Need Diagnostic Pre-Ablation Iodine-123 Scintigraphy to Optimize Treatment?

Diagnostics ◽

10.3390/diagnostics11030553 ◽

2021 ◽

Vol 11 (3) ◽

pp. 553

Author(s):

Elizabeth de Koster ◽

Taban Sulaiman ◽

Jaap Hamming ◽

Abbey Schepers ◽

Marieke Snel ◽

...

Keyword(s):

Lymph Node ◽

Lymph Node Metastasis ◽

Thyroid Carcinoma ◽

Treatment Success ◽

Differentiated Thyroid Carcinoma ◽

Whole Body ◽

Thyroid Remnant ◽

Node Metastasis ◽

Unsuccessful Treatment

Changing insights regarding radioiodine (I-131) administration in differentiated thyroid carcinoma (DTC) stir up discussions on the utility of pre-ablation diagnostic scintigraphy (DxWBS). Our retrospective study qualitatively and semi-quantitatively assessed posttherapy I-131 whole-body scintigraphy (TxWBS) data for thyroid remnant size and metastasis. Findings were associated with initial treatment success after nine months, as well as clinical, histopathological, and surgical parameters. Possible management changes were addressed. A thyroid remnant was reported in 89 of 97 (92%) patients, suspicion of lymph node metastasis in 26 (27%) and distant metastasis in 6 (6%). Surgery with oncological intent and surgery by two dedicated thyroid surgeons were independently associated with a smaller remnant. Surgery at a community hospital, aggressive tumor histopathology, histopathological lymph node metastasis (pN1) and suspicion of new lymph node metastasis on TxWBS were independently associated with an unsuccessful treatment. Thyroid remnant size was unrelated to treatment success. All 13 pN1 patients with suspected in situ lymph node metastases on TxWBS had an unsuccessful treatment, opposite 19/31 (61%) pN1 patients without (p = 0.009). Pre-ablative knowledge of these TxWBS findings had likely influenced management in 48 (50%) patients. Additional pre-ablative diagnostics could optimize patient-tailored I-131 administration. DxWBS should be considered, especially in patients with pN1 stage or suspected in situ lymph node metastasis. Dependent on local surgical expertise, DxWBS is not recommended to evaluate thyroid remnant size.

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