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

To elucidate the significance of oxidative stress in the modulation of endothelial functions, we examined the effects of H(2)O(2) on the expression of two endothelium-derived vasoactive peptides, endothelin (ET) and adrenomedullin (Am), and their interaction. H(2)O(2) dose dependently suppressed ET secretion and ET-1 mRNA expression in bovine carotid endothelial cells (ECs). Menadion sodium bisulfate, a redox cycling drug, also decreased ET secretion in a dose-dependent manner. Catalase, a H(2)O(2) reductase, and dl-alpha-tocopherol (vitamin E) significantly inhibited H(2)O(2)-induced suppression of ET secretion. Downregulation of ET-1 mRNA under oxidative stress was regulated at the transcriptional level. In contrast, H(2)O(2) increased Am secretion (and its mRNA expression) accompanied by the augmentation of cAMP production. Am, as well as 8-bromo-cAMP and forskolin decreased ET secretion in a dose-dependent fashion. Furthermore, an anti-Am monoclonal antibody that we developed abolished H(2)O(2)-induced suppression of ET secretion at 6-24 h after the addition of H(2)O(2). H(2)O(2) increased the intracellular Ca(2+) concentration ([Ca(2+)](i)). Moreover, treatment with ionomycin, a Ca(2+) ionophore, and thapsigargin, an inhibitor of endoplasmic reticulum ATPase, decreased ET secretion dose dependently for 3 h. These results suggest that the production of ET was decreased via activation of the Am-cAMP pathway and by the elevation of [Ca(2+)](i) under oxidative stress. These findings elucidate the coordinate expression of two local vascular hormones, ET and Am, under oxidative stress, which may protect against vascular diseases.
 ...
PMID:Coordinate regulation of endothelin and adrenomedullin secretion by oxidative stress in endothelial cells. 1151 8

To compare different culture conditions for neuroprotection assays in cultured cortic neurons, we evaluated cell viability after H2O2 exposure in cells cultured with standard N2 and with the enriched B-27 developed by GIBCO, both serum-free supplements. The following additives/associations were compared: N2 (+N2), B-27 (+B-27), 10% FBS (+FBS), 1% FBS in combination with N2 (FBS/N2) or N2 supplement preceded by an 1 hour precoating with 10% FBS (N2 + precoated). Our data demonstrated that B-27 is as efficient as 10% FBS to support neuronal growth for more than a week. As shown by phase-contrast optics cells grown in N2 started degenerating within 24-48 hours although measurable absorbance was seen with MTT. The pre-coating procedure failed to modify substantially cell viability as compared with N2 alone. Dose-response curves for H2O2 to induce neuronal apoptosis were almost identical for B-27 and serum supplemented samples. Catalase (100 U/ml) or vitamin E (200 microM) prevented cell death in both culture conditions. Our results indicate that DMEM/B-27 provides a serum-free cell culture environment that allows neurons to grow with optimal cell viability, comparable to that obtained with serum. We conclude that this culture condition reveals as a useful tool to test the efficacy of neuroprotectants when a serum free medium is required.
 ...
PMID:Hydrogen peroxide-induced neurotoxicity in cultured cortical cells grown in serum-free and serum-containing media. 1156 11

Oxidative stress has been implicated in the pathogenesis of both heart hypertrophy and heart failure. Hypertrophied heart, in response to pressure overload, is associated with an increase in antioxidant capacity and a decrease in oxidative stress. However, in the hypertrophied heart due to energy metabolic disorder, antioxidant capacity has not been investigated. Antioxidant changes in juvenile visceral steatosis (JVS) mice, a model of heart hypertrophy due to disorder of fatty-acid oxidation, were examined at 4 weeks (developing hypertrophy stage) and 8 weeks of age (established hypertrophy stage). Superoxide dismutase activity in the JVS mice was higher than that in control mice at 4 weeks of age and was not different from that in the control mice at 8 weeks of age. Glutathione peroxidase activity in the JVS mice at 8 weeks of age was lower than that in the control mice. Catalase activity showed no significant differences between the control and the JVS mice. Lipid peroxidation in the JVS mice was significantly reduced at 4 weeks of age and increased toward control levels at 8 weeks of age. The levels of vitamin E in the heart were increased in the JVS mice at 8 weeks of age. To determine whether antioxidants affect the pathogenesis of hypertrophy in this model, long-term treatments of vitamin E and 2-mercaptopropionyl glycine were performed. Vitamin E treatment partially reduced the heart hypertrophy in these mice. The present study shows that heart hypertrophy in the JVS mice is accompanied with increased antioxidant capacity as indicated in other animal models of heart hypertrophy. The precise mechanism of heart hypertrophy in JVS mice is still unknown, but oxidative stress may play a role in the pathogenesis of heart hypertrophy.
 ...
PMID:Antioxidant changes in the hypertrophied heart due to energy metabolic disorder. 1160 89

Catalase, Mn-superoxide dismutase (MnSOD) and Cu,Zn-superoxide dismutase (CuZnSOD) activities were studied in rat liver and kidney 6-48 h after CdCl(2) intraperitoneal administration or 10-30 days daily oral CdCl(2) intake in drinking water. This approach provided some indications as to the sensitivity of each enzyme to cadmium toxicity. These experiments showed that the formation of thiobarbituric acid reactive substance (TBARS) did not strictly depend on how well the antioxidant enzyme worked. From in vitro experiments it appeared that TBARS removal by vitamin E did not restore the three enzyme activities at all. As for cadmium's inhibitory mechanism on catalase activity, our data, obtained in the pH range 6.0-8.0, are a preliminary indication that the negative effect of this metal is probably due to imidazole residue binding of His-74 which is essential in the decomposition of hydrogen peroxide. Cadmium inhibition of liver mitochondrial MnSOD activity was completely removed by Mn(2+) ions, suggesting that the reducing effect on this enzyme is probably due to the substitution of cadmium for manganese. We also observed the antioxidant capacity of Mn(2+) ions, since they were able to normalize the increased TBARS levels occurring when liver mitochondria were exposed to cadmium. The reduced activity of CuZnSOD does not seem to be due to the replacement of Zn by Cd, nor to the peroxides formed. As this enzyme activity was almost completely recovered after 48 h, we hypothesize that the momentary inhibition is imputable to a cadmium/enzyme interaction. This causes some perturbation in the enzyme topography which is critical for its catalytic activity. The pathological implications linked to antioxidant enzyme disorders induced by cadmium toxicity are discussed.
 ...
PMID:Molecular inhibitory mechanisms of antioxidant enzymes in rat liver and kidney by cadmium. 1220 41

The aim of this study was to determine the effects of Hippophae rhamnoides L. extract (HRe-1) and also vitamin E as a positive control on nicotine-induced oxidative stress in rat blood, specifically alterations in erythrocyte malondialdehyde (MDA) level, activities of some erythrocyte antioxidant enzymes, and plasma vitamin E and A levels. The groups were: nicotine (0.5 mg/kg/d, intraperitoneal, i.p.); nicotine+vitamin E (75 mg/kg/d, intragastric, i.g.); nicotine+HRe-1 (1 ml/kg/d, i.g.); and control group (receiving only vehicles). There were 8 rats per group and the supplementation period was 3 weeks. Nicotine-induced increase in erythrocyte MDA level was prevented by both HRe-1 and vitamin E. Nicotine-induced decrease in erythrocyte superoxide dismutase (SOD) activity was prevented by HRe-1, but not vitamin E. HRe-1 increased the erythrocyte glutathione peroxidase (GSH-Px) activity compared with nicotine and the vitamin E groups. Catalase activity was not affected. Vitamin E supplementation increased plasma vitamin E level. Plasma vitamin A level was higher in both vitamin E and HRe-1 supplemented groups compared with nicotine and control groups. The results suggest that HRe-1 extract can be used as a dietary supplement, especially by people who smoke, in order to prevent nicotine-induced oxidative stress.
 ...
PMID:Beneficial effects of Hippophae rhamnoides L. on nicotine induced oxidative stress in rat blood compared with vitamin E. 1223 Jan 3

Amyloid-beta protein (A beta) deposition in the cerebral vascular walls is one of the key features of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D). A beta(1-40) carrying the 'Dutch' mutation (HCHWA-D A beta(1-40)) induces pronounced degeneration of cultured human brain pericytes. In this study, we aimed to identify inhibitors of A beta-induced toxicity in human brain pericytes. The toxic effect of HCHWA-D A beta(1-40) on human brain pericytes was inhibited by co-incubation with catalase, but not with superoxide dismutase, glutathione or vitamin E analogue Trolox. Catalase interacts with A beta, both in cell cultures and in cell-free assays, and has a prominent effect on the amount and conformational state of A beta binding to the cell surface of human brain pericytes. This activity of catalase is likely based on its ability to bind and slowly degrade A beta and not by its usual capacity to convert hydrogen peroxide. Our data confirm that assembly of A beta at the cell surface of human brain pericytes is a crucial step in A beta-induced cellular degeneration of human brain pericytes. Inhibition of fibril formation at the cell surface could be an important factor in therapy aimed at reducing cerebral amyloid angiopathy.
 ...
PMID:Inhibition of amyloid-beta-induced cell death in human brain pericytes in vitro. 1236 10

The aim of the present study was to investigate the effects of treatment with antioxidant stobadine (ST) on the activities of enzymes related with pentose phosphate pathway and glutathione-dependent metabolism and the other markers of oxidative stress in brain and peripheral organs of diabetic rats, and to compare the effects of ST treatment alone with the effects of treatments with another antioxidant vitamin E and ST plus vitamin E. Rats were made diabetic by the injection of streptozotocin (STZ; 55 mg/kg IP), and, 2 days later, some control and diabetic rats were left untreated or treated with ST (24.7 mg/kg/day, orally), vitamin E (400-500 U/kg/day, orally), or both substances together. In the brain, although 6-phosphogluconate dehydrogenase activity (6-PGD) did not change, glucose-6-phosphate dehydrogenase activity (G-6PD) was markedly increased in diabetic rats compared with controls; only combined treatment with ST and vitamin E produced a partial prevention on this alteration. The aorta G-6PD and 6-PGD of diabetic rats were 52% and 36% of control values, respectively. Neither single treatments with each antioxidant nor their combination altered the G-6PD and 6-PGD in aorta of diabetic rats. Glutathione peroxidase (GSHPx) activity was increased by STZ-diabetes in brain, heart, and kidney. In diabetic brain, vitamin E alone or combination with ST kept GSHPx at normal levels. Diabetes-induced stimulation in GSHPx did not decrease in response to the treatment with vitamin E in heart and kidney, but was greatly prevented by ST alone. The activity of glutathione reductase (GR) was decreased in brain and heart of diabetic rats. The treatment with each antioxidant or with a combination of both agents completely prevented this deficiency and resulted in further activation of GR in diabetic tissues. Glutathione S-transferase (GST) activity did not significantly change in diabetic brain and aorta. GST was stimulated by all treatment protocols in the brain of diabetic rats and was depressed in aorta of control rats. Catalase (CAT) was activated in diabetic heart but depressed in diabetic kidney. Diabetes-induced abnormalities in CAT activity did not respond to vitamin E alone in heart, was moderately ameliorated by the treatment with this vitamin in kidney, and was completely prevented by ST alone in both tissues. Superoxide dismutase (SOD) activity of brain and heart was unchanged by the diabetes but inhibited in diabetic kidney after the treatment ST alone or ST plus vitamin E. The lipid peroxidation (MDA) was increased in diabetic brain and heart. ST or vitamin E alone partly prevented diabetes-induced increase in MDA in brain and heart; however, antioxidant combination achieved a completely amelioration in MDA of these tissues of diabetic rats. Kidney MDA levels were similar in control and untreated diabetic animals. ST and vitamin E treatments, when applied separately or together, significantly reduced kidney MDA in both control and diabetic rats; and the combined effect of antioxidants was greater than that of each alone. These results are consistent with the degenerative role of hyperglycemia on cellular reducing equivalent homeostasis and antioxidant defense, and provide further evidence that pharmacological intervention of different antioxidants may have significant implications in the prevention of the prooxidant feature of diabetes and protects redox status of the cells.
 ...
PMID:Pentose phosphate pathway, glutathione-dependent enzymes and antioxidant defense during oxidative stress in diabetic rodent brain and peripheral organs: effects of stobadine and vitamin E. 1271 33

Methanol is primarily metabolized by oxidation to formaldehyde and then to formic acid. These processes are accompanied by formation of superoxide anion and hydrogen peroxide. This paper reports the in vitro antioxidant effect of vitamin E on isolated hepatocytes of folic acid deficient rats rendered so as to emulate a human hepatocyte model. These hepatocytes were treated with 320 microM of methanol per million cells and incubated for 30 min. The microsomal fraction of these hepatocytes showed a decreased level of superoxide dismutase (SOD), with increase in lipid peroxidation (LPO) shown by increase in recorded levels of malondialdehyde (MDA). Catalase activity was shown to be increased. Levels of reduced glutathione (GSH) were decreased and the activity of glutathione peroxidase (GSH-Px) and of glutathione reductase (GSSG-R) were not altered. The hepatocytes of folate deficient rats pretreated with vitamin E, when subjected to methanol treatment, showed no significant change in SOD levels and a significant decrease in MDA levels. The catalase activity in this group of animals showed a highly significant decrease. These animals had normal levels of GSH, while a significant fall in GSH-Px and GSSG-R levels were observed. These results suggest that Vitamin E exerts a protective effect on hepatocytes by acting as a free radical scavenger, proving its usefulness in treating methanol toxicity.
 ...
PMID:In vitro effect of methanol on folate-deficient rat hepatocytes. 1282 Dec 9

Piper species, commonly used in diet and traditional medicine were assessed for their antioxidant potential. Catalase activity was predominated in Piper longum, followed by Piper cubeba, green pepper, Piper brachystachyum and Piper nigrum. P. nigrum was richest in glutathione peroxidase and glucose-6-phosphate dehydrogenase, green pepper was richest in peroxidase and vitamin C while vitamin E was more in P. longum and P. nigrum. P. brachystachyum and P. longum were rich sources of vitamin A. All the Piper species had GSH content of around 1 to 2 nM/g tissue. The antioxidant components of Piper species constitute a very efficient system in scavenging a wide variety of reactive oxygen species. Antioxidant potential of Piper species was further confirmed by their ability to curtail in vitro lipid peroxidation by around 30-50% with concomitant increase in GSH content.
 ...
PMID:Enzymatic and non-enzymatic antioxidants in selected Piper species. 1525 5

The regional accumulation of aluminium in the brain of male albino Wistar rats was investigated following 4 weeks of administration by intraperitoneal injection of aluminium lactate (10mg aluminium/kg body weight). The consequences of concomitant dietary vitamin E (5, 15, or 20 mg vitamin E/g of food) were also studied. Rat brains were dissected into functional regions, for the measurement of aluminium and markers of oxidative stress. Plasma aluminium levels were increased in all groups of animals receiving aluminium lactate (p < 0.01), and these levels were significantly reduced in rats receiving concomitant vitamin E (p < 0.05). In the group of rats receiving aluminium alone, levels of brain tissue aluminium were increased in all regions of brain examined (p< 0.01). Brain tissue aluminium levels were reduced by concomitant dietary vitamin E. Catalase and reduced glutathione levels were both reduced in several regions of brain in animals treated with aluminium (p < 0.05). Aluminium treatment was not associated with a significant increase in reactive oxygen species (ROS) generation (p > 0.05), although ROS production was attenuated by dietary vitamin E (p < 0.05) in some regions.
 ...
PMID:Regional accumulation of aluminium in the rat brain is affected by dietary vitamin E. 1548 64


<< Previous 1 2 3 4 5 6 7 Next >>