Reversible inhibition and irreversible inactivation of catalase in presence of hydrogen peroxide

Lardinois, Olivier M.; Mestdagh, Michèle; Rouxhet, Paul

doi:10.1016/0167-4838(96)00043-x

Cited by 131 publications

(109 citation statements)

References 55 publications

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“…CAT from a number of animals including rats is prone to oxidative damage and undergoes transition from the usual ␣ phase of activity to a less active or inactive ␤ phase. 29 The recovery in both protein and activity of CAT following a brief course of high-dose antioxidant therapy with concomitant improvement of other antioxidants in the livers of Ob rats supports our contention that a major cause of the decrease in CAT in Ob rats is oxidative stress. The decrease in CAT will further exacerbate the existing oxidative stress.…”

Section: Discussionsupporting

confidence: 70%

Oxidative Stress in Fatty Livers of Obese Zucker Rats: Rapid Amelioration and Improved Tolerance to Warm Ischemia With Tocopherol

2001

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Fatty livers in humans and rats are less tolerant of ischemia, endotoxin, and alcohol. We hypothesized that fatty livers of obese (Ob) Zucker rats are oxidatively stressed and oxidative stress could be relieved by antioxidant treatment, leading to improved tolerance to ischemia. Total glutathione (GSH), tocopherol (TOC), ascorbic acid (AA), catalase (CAT), superoxide dismutase (SOD), and selenium-glutathione peroxidase (Se-GPx) were measured in the livers of Ob and lean (Ln) Zucker rats before and after treatment with high-dose TOC and ascorbate. Also, survival in treated Ob rats following a lethal 90 minutes of partial in vivo warm ischemia was examined. Fatty livers of Ob rats contained significantly less GSH, TOC, and CAT, in comparison with livers of Ln rats. Immunoblotting showed significantly decreased CAT protein without changes in mRNA in fatty livers. There were no significant differences in AA, SOD, and Se-GPx between the 2 groups. Pretreatment with TOC and ascorbate over 48 hours completely corrected the decreases in GSH, TOC, and CAT. Most importantly, TOC with or without ascorbate pretreatment significantly improved survival in Ob rats following ischemia in a dosedependent manner. Fatty livers in humans and experimental animals are more prone to a variety of insults such as ischemia/reperfusion (I/ RP), endotoxin, and alcohol. Nonalcoholic steatohepatitis and its progression to cirrhosis are well-defined clinical entities. 1 Recipients of human donor livers with moderate or severe steatosis have decreased graft and patient survival. 2 Although exact figures are not available, it is believed that as many as 30% of donor livers have varying degrees of steatosis on routine microscopic examination. About 10% of donor livers are not used for transplantation because of moderate to severe steatosis, and this worsens the current shortage of livers. 2 Treatment regimens that will improve tolerance of fatty livers to the aforementioned insults are needed, and would benefit a diverse group of patients.Two rodent models of fatty liver, the genetically obese (Ob) and lipotrope-deficient diet models, are used in the laboratory to further investigate the problems associated with fatty livers. Abnormalities in sinusoidal microcirculation, 3,4 mitochondrial oxidative phosphorylation including a decrease in adenosine triphosphate production, 5,6 and dysregulation of cytokine production 7 are some of the mechanisms that have been associated with the increased injury to fatty livers in both rodents and humans. Oxidative stress has recently been postulated to be a common feature in fatty livers of diverse etiologies. 1 Lipid peroxidation products in the liver are increased in both models of rat fatty liver. 8,9 Reactive oxygen intermediates are key mediators of I/RP injury in solid organs. Thus, a 2-step oxidative injury comprised of a chronic oxidative stress before and an additional acute oxidative stress following I/RP may explain the increased injury sustained by fatty livers following both cold and warm ischemia.To...

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Section: Discussionsupporting

confidence: 70%

Oxidative Stress in Fatty Livers of Obese Zucker Rats: Rapid Amelioration and Improved Tolerance to Warm Ischemia With Tocopherol

2001

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“…Because GPX is able to convert hydrogen peroxide to water and oxygen, it is tempting to speculate that the training-induced augmentation of GPX activity results in a reduction in cellular hydrogen peroxide levels and consequently, the elimination of substrate inhibition of Cat. 29 This might explain the increase in Cat and GPX activity in CHF patients seen with exercise training, despite the fact that no change occurred at the mRNA or protein level. Nevertheless, because GPX and Cat expression was not normalized, these data suggest that 6 months of exercise training are not sufficient to correct the impaired transcription of GPX and Cat in CHF.…”

Section: Influence Of Exercise Training On Expression Of Radical Scavmentioning

confidence: 99%

“…Moreover, it is also tempting to speculate that the decline in GPX activity results in accumulation of hydrogen peroxide within the cell, finally leading to substrate inhibition of Cat. 29 The close inverse correlation between TNF-␣ protein levels in SM and Cat activity also suggests that this inflammatory cytokine inhibits Cat directly, but the exact mechanism remains to be determined.…”

Section: Expression Of Radical Scavenger Enzymes In Sm Of Patients Wimentioning

confidence: 99%

Antioxidative Effects of Exercise Training in Patients With Chronic Heart Failure

et al. 2005

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Background-In chronic heart failure (CHF), cross-talk between inflammatory activation and oxidative stress has been anticipated in skeletal muscle (SM). The role of the radical scavenger enzymes superoxide dismutase (SOD), catalase (Cat), and glutathione peroxidase (GPX), which remove oxygen radicals, has never been assessed in the SM in this context. Moreover, it remains unknown whether exercise training augments the activity of these enzymes in CHF. Methods and Results-Twenty-three patients with CHF were randomized to either 6 months of exercise training (T) or a sedentary lifestyle (C); 12 age-matched healthy subjects (HS) were studied in parallel. Activity of Cat, SOD, and GPX was assessed in SM biopsies before and after 6 months (6 months). Oxidative stress was determined by measuring nitrotyrosine formation. SOD, Cat, and GPX activity was reduced by 31%, 57%, and 51%, respectively, whereas nitrotyrosine formation was increased by 107% in SM in CHF (PϽ0.05 versus HS). In CHF, exercise training augmented GPX and Cat activity in SM by 41% (PϽ0.05 versus before and group C) and 42% (PϽ0.05 versus before and group C), respectively, and decreased nitrotyrosine production by 35% (from 3.8Ϯ0.4% tissue area before to 2.5Ϯ0.3% after 6 months; PϽ0.05 versus before). Conclusions-The reduced activity of major antioxidative enzymes in the SM of CHF patients is associated with increased local oxidative stress. Exercise training exerts antioxidative effects in the SM in CHF, in particular, due to an augmentation in activity of radical scavenger enzymes.

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“…CAT has the highest turnover rate among all enzymes, one molecule of CAT can convert approximately 6 million molecules of H2O2 to H2O and O2 per minute [62] and the pH optimum obtained from different sources is 6.8-7.5. The enzyme can function in 2 ways: and phases [107,108].…”

Section: Catalase (Cat)mentioning

confidence: 99%

Oxidative Processes and Antioxidative Metaloenzymes

Vašková¹,

Vaško²,

Kron³

2012

Antioxidant Enzyme

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Reversible inhibition and irreversible inactivation of catalase in presence of hydrogen peroxide

Cited by 131 publications

References 55 publications

Oxidative Stress in Fatty Livers of Obese Zucker Rats: Rapid Amelioration and Improved Tolerance to Warm Ischemia With Tocopherol

Oxidative Stress in Fatty Livers of Obese Zucker Rats: Rapid Amelioration and Improved Tolerance to Warm Ischemia With Tocopherol

Antioxidative Effects of Exercise Training in Patients With Chronic Heart Failure

Oxidative Processes and Antioxidative Metaloenzymes

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