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Query: UNIPROT:P30044 (
antioxidant enzyme
)
8,037
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Feeding diets depleted of vitamin E and Se to cattle can induce a disease known as nutritional degenerative myopathy. It is believed that an increased peroxidative challenge in muscle is involved in the pathogenesis of this disease. A number of species can up-regulate the activity of some antioxidant enzymes, including glutathione reductase (EC 1.6.4.2), glutathione transferase (EC 2.5.1.18), glucose-6-phosphate dehydrogenase (EC 1.1.1.49), catalase (EC 1.11.1.6), and superoxide dismutase (EC 1.15.1.1), in an attempt to mitigate the effects of a peroxidative challenge. A 2 x 2 factorial study was set up to examine possible changes in the activities of these antioxidant enzymes in muscles of ruminant calves fed on diets low in either vitamin E or Se. Four groups of four calves each were fed on a basal diet of NaOH-treated barley which was supplemented with alpha-tocopherol or Se or both for a total of 50 weeks. Calves fed on diets depleted of vitamin E, but not those fed on diets low in Se, developed subclinical myopathy, as judged by increases in the activity of plasma creatinine kinase (EC 2.7.3.2), and had increased muscle concentrations of two indices of lipid peroxidation, namely thiobarbituric acid-reactive substances, with and without ascorbate activation. Feeding diets depleted of vitamin E and diets low in Se both increased muscle activities of glucose-6-phosphate dehydrogenase in heart, biceps and supraspinatus. This change may have occurred in an attempt to maintain intracellular pools of reduced glutathione. No other changes in
antioxidant enzyme
activity were observed.
Br J Nutr 1993
Sep
PMID:Antioxidant enzyme activity in the muscles of calves depleted of vitamin E or selenium or both. 826 Apr 86
The essential nutrients zinc (Zn) and selenium (Se) provide an antioxidant function to animal cells by very different mechanisms. Se is an integral part of Se-dependent glutathione peroxidases, a group of water-soluble enzymes that catalyze the destruction of water-soluble and, in some cases, membrane-bound hydroperoxides. In dietary Se deficiency, Se-dependent glutathione peroxidase activities are decreased; at Se intakes above that which is required for optimal growth, there is a slight to moderate increase in Se-dependent glutathione peroxidase activities. Because of the enzymatic nature of the major role of Se as an antioxidant, Se can be categorized as having a general antioxidant function, controlling peroxide levels in cells by degrading hydroperoxides. On the other hand, Zn functions as an antioxidant only at specific sites, and is not a required cofactor for an
antioxidant enzyme
. Although Zn plays a structural role in the enzyme Cu, Zn superoxide dismutase, the activity of this enzyme is not decreased in Zn deficiency and its activity is usually depressed at high Zn intakes. Zn may function as a site-specific antioxidant by two mechanisms. Firstly, it competes with Fe and Cu for binding to cell membranes and some proteins, displacing these redox-active metals and making them more available for binding to ferritin and metallothionein, respectively. Secondly, Zn binds the sulfhydryl groups in proteins, protecting them from oxidation. Zn status does not directly control tissue peroxide levels but can protect specific molecules against oxidative and peroxidative damage.
Can J Physiol Pharmacol 1993
Sep
PMID:Zinc and selenium, site-specific versus general antioxidation. 831 37
Human blood mononuclear cells exposed to visible light increase their
antioxidant enzyme
(superoxide dismutase, catalase, and glutathione peroxidase) and DT-diaphorase activities. The activities of CuZn-superoxide dismutase (3.70 +/- 0.25 U/mg protein), catalase (4.60 +/- 0.39 U/mg protein), and DT-diaphorase (1.40 +/- 0.11 mumol DCPIP/min.mg protein) increased 1.5-fold when mononuclear cells were exposed at 38 W/m2 for 4 h. Se-containing glutathione peroxidase activity (6.76 +/- 0.21 mU/mg protein) increased 1.3 times after 3 h of exposure to 38 W/m2. Conversely, Mn-superoxide dismutase (2.20 +/- 0.20 U/mg protein), succinate dehydrogenase (0.86 +/- 0.04 mumol DCPIP/min.mg protein), and cytochrome oxidase (0.54 +/- 0.04 min-1 (k')/mg protein) activities remained constant during this period of exposure. The treatment of cells with cycloheximide prevented the response triggered by light exposure. These results introduce new insight to the adaptive response of human cells to light stress suggesting that: (a) the response observed might be ascribed to synthesis of stress proteins rather than to activation of a preexisting pool, and (b) that DT-diaphorase and CuZn-superoxide dismutase may operate biologically in a concerted fashion resulting in antioxidant activity.
Arch Biochem Biophys 1993
Sep
PMID:Induction of antioxidant enzymes and DT-diaphorase in human blood mononuclear cells by light stress. 837 61
1. Tissue damage in idiopathic pulmonary fibrosis is due in part to oxidant-antioxidant imbalance. 2. We evaluated the serum levels of the
antioxidant enzyme
Cu/Zn superoxide dismutase (EC 1.15.1.1) in 25 patients with idiopathic pulmonary fibrosis, 34 patients with sarcoidosis and 40 healthy control subjects by an enzyme immunometric assay. 3. We found that patients with idiopathic pulmonary fibrosis have higher serum Cu/Zn superoxide dismutase levels than control subjects and patients with sarcoidosis. In addition, serum Cu/Zn superoxide dismutase levels correlate with disease severity indexes in patients with idiopathic pulmonary fibrosis. 4. The increase in serum Cu/Zn superoxide dismutase level in idiopathic pulmonary fibrosis could depend on degranulation of activated neutrophils or release from damaged cells. To elucidate the contribution of neutrophil degranulation we determined the polymorphonuclear cell elastase level in the same specimens. We found a strong correlation between serum Cu/Zn superoxide dismutase and polymorphonuclear cell elastase activities, and, in patients with idiopathic pulmonary fibrosis, we observed higher levels of polymorphonuclear cell elastase than in control subjects and patients with sarcoidosis, which correlated positively with disease severity indexes. 5. Cu/Zn superoxide dismutase can catalyse the dismutation of O2 into H2O2 and generate OH.. These oxygen radicals are probably the major factors responsible for tissue damage (in particular, alveolar and endothelial cells) and fibrosis in experimental lung injury.(ABSTRACT TRUNCATED AT 250 WORDS)
Clin Sci (Lond) 1993
Sep
PMID:Elevated serum superoxide dismutase levels correlate with disease severity and neutrophil degranulation in idiopathic pulmonary fibrosis. 840 8
The alterations of superoxide dismutase iso-enzyme (Cu,Zn-SOD and Mn-SOD) activities, contents, and mRNA expressions with aging were studied in rat soleus muscle (SO) and extensor digitorum longus muscle (EDL). The activity and content of Cu,Zn-SOD in both muscles were significantly higher in old rats (24 months old) than in young rats (4 months old), whereas those of Mn-SOD showed no difference between young and old rats. After normalization to citrate synthase (CS) activity, however Mn-SOD/CS ratio in SO also showed the age-related increase. Moreover, the activities of other major antioxidant enzymes, glutathione peroxidase (GPX) and catalase (CAT), indicated age-related increases only in SO. As for the expressions of mRNAs for SOD iso-enzymes, that of Cu,Zn-SOD in either muscle showed no significant change with aging, unlike its activity and content, although that of Mn-SOD was decreased with aging only in EDL. Thus, aging appeared to raise the level of
antioxidant enzyme
system in rat skeletal muscle. However, the resistance of Cu,Zn-SOD and Mn-SOD to oxidative stress accompanied by aging was different, the former being obviously greater than the latter. Such changes also differed in muscle fiber type suggesting that fast-twitch fibers are more susceptible to age-related oxidative stress than slow-twitch fibers.
Mech Ageing Dev 1995
Sep
29
PMID:Alterations of superoxide dismutase iso-enzyme activity, content, and mRNA expression with aging in rat skeletal muscle. 871 78
This hypothesis states that magnesium and copper (Cu) deficiency as well as high arterial oxygen pressure may contribute to the pathogenesis of retinopathy of prematurity (ROP), a major cause of blindness in very low birthweight preterm infants. Infants at highest risk have severe respiratory distress with hypoxia and require prolonged oxygen supplements. The retina is a multilayer sheet of neural tissue very rich in polyunsaturated fatty acids (PUFAs), oxygen, and mitochondria, with the highest oxygen consumption of all body tissues. Oxygen free radicals which are generated during metabolism cause lipid peroxidation of the PUFA-rich membranes, impairing retinal function. Magnesium and copper deficiencies provide less protection from oxidative injury which damages neurosensory tissue critical for photodetection. Protective
antioxidant enzyme
activity is reduced in magnesium and copper deficiency. There is some evidence for a raised level of vasoconstrictor thromboxane A2 (TXA2) in respect to vasodilator prostacyclin (PGI2), which would promote vasoconstriction. Deficiency of magnesium and of copper increase synthesis of TXA2 and decreases synthesis of PGI2. Sustained vasoconstriction leads to vascular occlusion, retinal ischaemia, reactive proliferation of retinal vasculature, and the final stages of ROP. Abundant magnesium and copper may protect the retina from developing ROP.
Magnes Res 1995
Sep
PMID:Hypothesis: the possible role of magnesium and copper deficiency in retinopathy of prematurity. 884 91
The purpose of this review is to discuss the adaptive strategies of mammalian respiratory muscles in response to whole-body endurance exercise training. It is now clear that endurance training results in small (i.e., 20-30%) but significant increases in mitochondrial enzyme activity and the activities of key antioxidant enzymes (i.e., superoxide dismutase and glutathione peroxidase) within the rodent diaphragm. Interestingly, the magnitude of this training-induced increase in costal diaphragmatic oxidative and
antioxidant enzyme
activity is relatively independent of the exercise duration and intensity. Although the crural diaphragm of rodents is also capable of increasing its oxidative and antioxidant capacity in response to endurance training, high-to moderate-intensity exercise of long duration is required to promote these changes. Endurance training also increases the oxidative capacity of other key rodent inspiratory muscles, such as the parasternal intercostals and external intercostals. Furthermore, endurance training results in small (approximately 10%) increased in the oxidative capacity of key abdominal (expiratory) muscles. Whether the improvement in oxidative capacity of respiratory muscles is of significant magnitude to result in improvement in respiratory muscle performance remains an unanswered question.
Med Sci Sports Exerc 1996
Sep
PMID:Adaptive strategies of respiratory muscles in response to endurance exercise. 888 98
We investigated the effects of aging and/or swimming training on the
antioxidant enzyme
system in diaphragm of mice. Young (2 months old) and old (26 months old) male mice were swimming-trained for 6 weeks (1 h/day, 5 days/week). Cu,Zn-Superoxide dismutase (Cu,Zn-SOD) activity was significantly upregulated with aging, and swimming training definitely enhanced the activity only in young mice. Neither aging nor swimming training had overt effect on Mn-SOD activity. Glutathione peroxidase activity in young mice was significantly increased after training, but not in old mice. Both of immunoreactive Cu,Zn-SOD and Mn-SOD were significantly increased with aging but were unaffected by swimming training. Consequently, physical training significantly enhanced the specific activity of Cu,Zn-SOD in young mice, but not in old mice. Meanwhile, swimming training significantly increased xanthine oxidase activity in both age groups, the extent of the increase being greater in old mice than in young mice. We concluded that the
antioxidant enzyme
system in mouse diaphragm trends to be upregulated with aging, but that swimming training improved the system only in young mouse diaphragm.
Respir Physiol 1996
Sep
PMID:Effects of aging and/or training on antioxidant enzyme system in diaphragm of mice. 893 Nov 79
This study was conducted to observe the effects of endurance exercise training on
antioxidant enzyme
activity in the liver and gastrocnemius muscle of rats being fed dietary casein and soy protein. The respective influences of dietary casein and soy protein on the activity of antioxidant enzymes were also compared. Thirty-nine male Wistar rats, aged 3 weeks, were randomly assigned to six groups: a normal protein control group, a normal protein endurance training group, a casein protein control group, a casein protein endurance training group, a soy protein control group, and a soy protein endurance training group. The endurance exercise training groups were adapted to a treadmill for 2 weeks prior to the date the rats were forced to run for 60 min at 25 m/min, 5 days/week for 12 weeks. We found that
antioxidant enzyme
activity in the gastrocnemius muscle was neither effected by the dietary proteins (casein and soy protein) nor by the above endurance exercise training load. However, hepatic Cu,Zn-SOD activity increased significantly for the dietary casein and soy protein diet groups as compared with the normal protein diet group (P < 0.01). Furthermore, significant increases both in hepatic Cu,Zn-SOD activity in the normal protein group and hepatic GSHpx activity in the casein and soy protein groups were observed when rats were loaded with 25 m/min of endurance exercise training (P < 0.01). These results suggest that, under the above experimental conditions, a casein or soy protein diet increase hepatic Cu,Zn-SOD activity, while endurance exercise training is effective in increasing hepatic Cu;Zn-SOD activity on a normal protein diet and in increasing hepatic GSHpx activity for cysteine and methionine deficient diets.
Appl Human Sci 1996
Sep
PMID:Antioxidant enzymes response to endurance exercise training and dietary proteins in rat skeletal muscle and liver. 897 3
The effects of chronic ethanol intoxication on the open-field behavior, on
antioxidant enzyme
activities, and the degree of lipid peroxidation were investigated. Rats consuming a liquid diet containing 7% ethanol for 4, 7, 14, or 21 days exhibited a significantly decreased ambulation activity, accompanied by a reduced frequency and duration of explorative rearing in an open-field task 4, 7, and 14 days after chronic ethanol ingestion, whereas presumed adaptation to the neurologic effects of ethanol was observed on day 21. Changes in the activities of glutathione peroxidase (GSH-Px): glutathione reductase (GSH-R), and catalase, and in the content of reduced glutathione (GSH) in blood samples were determined by means of biochemical methods. The degree of lipid peroxidation was measured via thiobarbituric acid assays. Chronic ethanol ingestion elicited a significant increase in GSH-Px activity (by a maximum of approximately 32% on day 14), whereas opposite alterations in GSH-R and catalase activities were recorded (49% of the control value on day 4 and 17% on day 21, respectively). Highly elevated contents of thiobarbituric acid reactive substances reflected extensive lipid peroxidation processes throughout the experiment. These changes indicate that ethanol toxicity induces profound changes in explorative behavior, mediated, at least partly, by changes in the free radical metabolism.
Pharmacol Biochem Behav 1997
Sep
PMID:Chronic ethanol ingestion-induced changes in open-field behavior and oxidative stress in the rat. 926 91
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