Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adult rats show evidence of severe lung damage after 72h of continuous exposure to hyperoxia (96-98% O2). Treatment of adult rats with a solution of Plasmanate, inadvertently contaminated with endotoxin-producing organisms, or with purified endotoxin itself markedly altered the lung toxicity associated with hyperoxic exposure (survival in treated animals = 110/113 [97%] versus survival in untreated animals = 56/172 [33%]). After 72h of hyperoxic exposure, the endotoxin-treated rats demonstrated significant increases in lung superoxide dismutase, catalase, and glutathione peroxidase activity, a protectant enzyme response not seen in untreated adult rats. The basis for endotoxin's protective effect from hyperoxic lung damage is believed to be related to the stimulated increase in activity of the pulmonary antioxidant enzyme defense system. Some previously known actions of endotoxin are speculated to also serve a protective function by opposing some of the usual detrimental effects of high concentrations of O2 on the lung.
 ...
PMID:The role of endotoxin in protection of adult rats from oxygen-induced lung toxicity. 62 Dec 74

Neonatal and adult animals of five species were exposed to 95+% O2. Survival time and changes in lung antioxidant enzyme activity (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GP)) in response to hyperoxia were determined. Adult animals succumbed to O2 lung toxicity in 3--5 days. Neonatal rats, mice and rabbits showed minimal lung changes after 7 days of hyperoxic exposure and these same neonatal animals showed rapid and significant increases in lung antioxidant enzyme activities. In contrast, neonatal guinea pigs and hamsters had no lung antioxidant enzyme response to hyperoxia and these neonates died in 95+% O2 as readily as their respective parent animals. Results from an in vitro hyperoxic exposure system suggest that the lack of enzymic response of the guinea pig (and hamster) neonates to O2 challenge is due to an inherent pulmonary biochemical unresponsiveness rather than to a deficiency of a necessary "serum factor." The results of this species and age study support the important role of the lung antioxidant enzyme defense system in protection of the lung from O2-induced injury.
 ...
PMID:Oxygen toxicity in neonatal and adult animals of various species. 73 May 65

Polyclonal antisera to manganese and copper-zinc superoxide dismutases, catalase, glutathione peroxidase (GPx), and isozymes of glutathione S-transferase (liver and placental isolates, GST-L and GST-P, respectively) were used to localize these enzymes in normal rat lung by immunostaining. Light-microscopic results, using an immunoperoxidase technique, were expanded on by electron-microscopic immunogold localization. The findings were consistent with previous biochemical work. However, both GPx and GST-P were predominantly localized to extracellular connective tissue of the lung. These findings demonstrate the basal antioxidant enzyme phenotypes for parenchymal lung tissue at light- and electron-microscopic levels. Significant components of enzymatic defense to oxidant stress are heterogeneously distributed throughout rat lung tissue including both epithelial cell surfaces and the extracellular matrix.
 ...
PMID:Immunolocalization of antioxidant enzymes and isozymes of glutathione S-transferase in normal rat lung. 128 3

Aberrant expression of the antioxidant enzyme glutathione peroxidase (GPx) could contribute to the etiology of rheumatoid arthritis (RA). However, previous enzyme activity studies examining this relationship were inconclusive. Indirect evidence for this relationship derives from the known efficacy of gold therapy in RA, since gold compounds specifically inhibit GPx. The hypothesis that variants of GPx are associated with RA was examined by two approaches: enzyme activity analysis and restriction fragment length polymorphism (RFLP) association analysis. No significant difference was found in whole blood GPx activity between 28 RA patients and 36 controls. GPx activity appeared to be independent of sex, race, or type of drug treatment. However, a statistically significant difference was found with respect to treatment responsiveness. RA patients classified as good responders to gold therapy, but who were no longer taking gold, had a significantly higher GPx activity compared to both the controls and good responders currently on gold therapy. Aberrantly high GPx activity could contribute to RA by generating excess oxidized glutathione, a potent collagenase activator. Gold therapy would reduce GPx activity to normal levels. The restriction enzyme Pvu II in conjunction with a GPx gene probe identified a useful RFLP (Al, 22 kbp; A2, 15 kbp) with allelic frequencies of A1 and A2 equal to 0.11 and 0.89, respectively, in the control population. No statistically significant association, however, could be demonstrated between this allelic variant of the GPx gene and RA.
 ...
PMID:Role of glutathione peroxidase in rheumatoid arthritis: analysis of enzyme activity and DNA polymorphism. 134 42

1. The effect of the increasing concentrations of CuSO4 and HgCl2 (0.01-0.3 mmol/l) on erythrocyte haemolysis and the activities of peroxide metabolism enzymes: superoxide dismutase, catalase, peroxidase and glutathione peroxidase was investigated in human erythrocytes and the nucleated red blood cells of marine fish (Dicentrarchus labrax). 2. The results show that both heavy metal ions had only little effect on haemolysis and antioxidant enzyme activities in human erythrocytes; in contrast the effect of heavy metals on fish erythrocytes was statistically significant when compared to control values. 3. Copper was found to have more pronounced effect than mercury on the erythrocytes of Dicentrarchus labrax; otherwise there were no significant differences between the toxic effects of both ions on human erythrocytes. 4. We suggest that the mechanism of copper-induced haemolysis may be different from that of mercuric ion in the erythrocytes of Dicentrarchus labrax.
 ...
PMID:The comparison of the effects of heavy metal ions on the antioxidant enzyme activities in human and fish Dicentrarchus labrax erythrocytes. 135 29

The defense system of aortic endothelial cells against oxidative stress was studied in alloxan-induced diabetic rabbits, and the effect of insulin on the antioxidant activities was estimated. Endothelial cells were prepared from 10 diabetic rabbits, 18 diabetic rabbits treated with insulin, and 10 age-matched controls after 17 days of diabetes. These cells were used for the estimation of glutathione (GSH) levels and its related enzyme activities. The antioxidant activities in these endothelial cells from diabetic rabbits were compared with those from control subjects. The concentration of GSH decreased in diabetic rabbits (1.6 +/- 0.2 nmol/mg protein [mean +/- SD] v 3.7 +/- 0.6 nmol/mg protein). Decreases in the activities of Cu, Zn-superoxide dismutase (Cu,Zn-SOD) (62.7 +/- 11.0 U/mg protein v 172.9 +/- 20.2 U/mg protein), catalase (7.6 +/- 2.1 U/mg protein v 12.3 +/- 3.2 U/mg protein), and GSH peroxidase (134.0 +/- 27.0 mU/mg protein v 179.1 +/- 26.2 mU/mg protein) were observed. The activities of other GSH-related enzymes such as GSH S-transferase or GSH reductase did not change in endothelial cells from diabetic rabbits. Most of these antioxidant activities were prevented when diabetic rabbits were treated with insulin (1 to 2 U/kg/d). These antioxidant activities were also determined in the diabetic liver and kidney. Similar decreases in the cellular defense activities and prevention of the decrease in activities by insulin were observed in the diabetic liver, while these antioxidant enzyme activities in the kidney were resistant to diabetic conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effect of insulin on impaired antioxidant activities in aortic endothelial cells from diabetic rabbits. 140 92

Undernutrition may exacerbate hyperoxia-induced lung injury, a finding that may be of significance in the early clinical management of the premature human infant. Addressing this specific problem, we found that 72 h of food restriction in guinea pig pups delivered 3 days preterm increased mortality rates among pups exposed to 95% oxygen (8/18) and yet had no effect on 21% oxygen (air)-exposed pups (0/10). Reduced tolerance of hyperoxic conditions was not, however, associated with increased lung injury, assessed as pulmonary microvascular leakage. Pulmonary antioxidant enzyme activities [Cu,Zn superoxide dismutase (SOD), Mn SOD, glutathione peroxidase, and catalase] were unaltered by starvation or hyperoxia. Lung glutathione concentration was slightly decreased after food restriction, whereas hyperoxic exposure did not change either lung or bronchoalveolar lavage fluid glutathione concentrations or lung antioxidant enzyme activities. Increased susceptibility to the lethal effects of oxygen in the starved preterm guinea pig pup could not be attributed to a deficiency of pulmonary antioxidant defenses.
 ...
PMID:Effect of food restriction on hyperoxia-induced lung injury in preterm guinea pig. 141 61

To determine if an enhancement in the fetal antioxidant enzyme (AOE) system by maternal dexamethasone (DEX) is specific to organ and dose, the lung and kidney of pups, whose mother received DEX (0.2 or 2 mg/kg) twice, were obtained on days 19 and 20 of gestation. Low-dose DEX increased the four AOE in the day-19 lung, but not in day-20 lung. High-dose DEX decreased the copper-zinc superoxide dismutase (SOD) and glutathione peroxidase in the lungs. Thus, the DEX-induced maturation of lung AOE is dependent on dose and timing. DEX enhanced the four AOE in the day-19 kidney at both doses. In the day-20 kidney, DEX enhanced the manganese SOD at the low dose and also catalase at the high dose, suggesting that DEX accelerates the maturation of kidney AOE as well.
 ...
PMID:Effect of dexamethasone on antioxidant enzymes in fetal rat lungs and kidneys. 142 Jun 13

Injury to the gastrointestinal tract by oxygen dependent processes is important in ischemia, inflammatory bowel disease, and necrotizing enterocolitis. The Caco-2 cell line is an important tool in assessing various gastrointestinal functions and offers a unique opportunity to assess gastrointestinal oxidant metabolism on a cellular level. However, some Caco-2 cell functions change with time after confluence. To determine if antioxidant enzyme activity changes during differentiation, Caco-2 cells were grown to confluence, and superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and specific mRNA content were quantitated. With time after confluence the enzymes demonstrated a small, but statistically significant increase in activity. Neither superoxide dismutase nor glutathione peroxidase mRNA levels correlated with enzyme activity changes. Catalase mRNA levels increased as catalase activity increased. Thus, differentiated Caco-2 cells express superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and the superoxide dismutase, glutathione peroxidase, and catalase genes. Superoxide dismutase activity and glutathione peroxidase activity do not correlate with mRNA levels, and suggest that regulation may be at a level other than transcription. The correlation between catalase activity and catalase mRNA suggests differentiation may occur at transcription. If Caco-2 cells are used to elucidate oxidative metabolism, changes in activities of antioxidant enzymes as a function of cell differentiation should be considered.
 ...
PMID:Antioxidant enzymes in the differentiated Caco-2 cell line. 142 66

Enzyme activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined in the liver as well as several specific brain regions of young and old Fischer-344 rats of both sexes. In the liver of male rats, activities of CAT as well as Mn-SOD were lower, while activities of Cu Zn-SOD were higher in old (30-month-old) rats than in young (7-month-old) ones. Activities of total SOD as well as GSH Px were comparable for young and old male rat livers. In contrast to male rats, in female rat livers, activities of CAT were significantly higher in old (28-months-old) rats, while activities of Mn-SOD were slightly (but significantly) higher in old rat livers. In old male rats, activities of Mn-SOD were significantly higher than in young males in several specific regions of the brain (the substantia nigra (s. nigra), striatum, hippocampus) but lower in the cerebellum. In particular, SOD activities in s. nigra, striatum and hippocampus in old male rats were several fold higher than corresponding values in young male rats. Activities of Cu Zn-SOD were generally unchanged with age. Activities of CAT as well as GSH-Px (both Se-dependent and non-Se-dependent forms) were also relatively unaffected by age. In female rat brains, activities of Mn-SOD as well as those of others all remained mostly unaffected by aging, although there was a general tendency of slightly higher activities in most cerebral regions for Mn-SOD in old female rats. Thus, age-related changes of these antioxidant enzymes in the liver and brain are markedly sex dependent and some enzyme activities (such as CAT in the liver) change in an opposite direction with age. Changes of Mn-SOD in the brain were markedly region-specific in male rats. Results suggest that the significance of the changes of these antioxidant enzyme activities during aging needs to be carefully interpreted, taking into consideration the fact that changes are markedly variable depending on sex as well as the organs and brain regions examined.
 ...
PMID:Age-related changes in antioxidant enzyme activities are region and organ, as well as sex, selective in the rat. 143 48


1 2 3 4 5 6 7 8 9 10 Next >>