Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.5.1.18 (glutathione S-transferase)
22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A comprehensive study on glutathione metabolism in rat heart and liver as a function of age was performed. In the heart, reduced glutathione, total glutathione, and the glutathione redox index showed a decrease during aging, while oxidized glutathione levels increased in 5-month-old rats with respect to the young animals and remained quite constant in 14- and 27-month-old rats. In the liver, the highest levels of reduced glutathione were found in the 2-month-old rats, while oxidized glutathione reached a peak at 5 months. Glutathione-associated enzymes showed age-related changes. Glutathione peroxidase, unaffected by aging in the heart, decreased in the liver of the 27-month-old rats. In the heart and the liver, the highest values of glutathione S-transferase were found at 5 months and 27 months, respectively. Glucose-6-phosphate dehydrogenase followed a similar trend in both heart and liver. Glutathione reductase also showed the same behaviour in heart and in liver, increasing in old rats with respect to the other age groups. A decrease in gamma-glutamylcysteine synthetase was found in the heart and liver of 27-month-old rats in comparison with the 2-month-old ones. In conclusion, a decreased antioxidant capability has been demonstrated in both heart and liver of old rats.
...
PMID:Glutathione metabolism in heart and liver of the aging rat. 791 19

The Long-Evans Cinnamon rat is a mutant strain that contracts hereditary hepatitis and, eventually, spontaneous hepatoma. Recently, abnormal copper accumulations in Long-Evans Cinnamon rat livers were shown to be genetically linked to the development of hepatitis. Because reduced glutathione and glutathione-related enzymes are known to play important roles in cellular resistance to transition metal toxicity, we determined the levels of reduced glutathione and glutathione-related enzymes in seven different tissues of Long-Evans Cinnamon and control Long-Evans Agouti rats. Of the enzymes examined, only hepatic glutathione peroxidase was markedly decreased in Long-Evans Cinnamon rats. Glutathione peroxidase content in the liver of Long-Evans Cinnamon rats was 39%, 53% and 58% of the control values at 9 (normal stage), 19 (acute hepatitis stage) and 27 (chronic hepatitis stage) wk of age, respectively. Northern-blot analysis revealed that messenger RNA levels of glutathione peroxidase in the livers of Long-Evans Cinnamon rats were about 40% of the control levels. The activity of glutathione S-transferase was slightly decreased in the livers of Long-Evans Cinnamon rats. These data suggest that the liver of the Long-Evans Cinnamon rat is poorly protected against active oxygen species, the production of which is enhanced in the presence of excess copper. Glutathione-reductase activity in the livers of Long-Evans Cinnamon rats increased to 166% and 148% of the control levels at 19 and 27 wk of age, respectively. No significant changes were observed in the activity of gamma-glutamylcysteine synthetase or in the content of total reduced glutathione in the liver of the Long-Evans Cinnamon rat.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Decreased expression of liver glutathione peroxidase in Long-Evans cinnamon mutant rats predisposed to hepatitis and hepatoma. 811 95

Antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glutathione S-transferases are thought to be the primary cellular defense against reactive oxygen species. Since pulmonary injury produced by oxidant air pollutants like ozone is highly focal, involving primarily the trachea and centriacinar areas of the lung, measurements of alterations in antioxidant enzyme activities in whole lung may substantially underestimate changes occurring in target areas of the respiratory tract. We have applied a technique for preparation of lung specimens from well-defined anatomic locations to determine whether the focal injury associated with ozone exposure is related to an uneven distribution of antioxidant enzyme activity in the respiratory tract. Our study compared enzyme activities in rat and monkey, species which differ considerably in sensitivity to ozone-induced injury (monkey > rat). The activities of glutathione S-transferase varied less than twofold between different airway subcompartments for both the rat and monkey. Pulmonary veins had approximately 50% of the activity of airways in both species. Glutathione peroxidase activity was slightly higher in proximal compared to distal airways of the rat but was evenly distributed at all airway levels in the monkey. In both species, activity in pulmonary veins was lower than that in airways. The activity of superoxide dismutase was similar in rat and monkey and marked differences were not observed in the various subcompartments studied. Similarly, catalase activity was relatively evenly distributed in rat airways but, in the monkey, the distal bronchiole and lobar bronchus had marginally higher activity than the trachea. We conclude that: (1) measurement of antioxidant enzyme activities in anatomic subcompartments within the lung is feasible using microdissected specimens, (2) antioxidant enzyme activity can vary in different subcompartments of the lung of the same species, (3) the pattern of variation in enzyme activity differs by the enzyme and by species, and (4) species and subcompartment differences in ozone injury are not due primarily to differences in the distribution of antioxidant enzyme activity.
...
PMID:Variation in antioxidant enzyme activities in anatomic subcompartments within rat and rhesus monkey lung. 823 64

Glutathione peroxidase was purified from the total membrane fractions of a yeast, Hansenula mrakii IFO 0895. The purified enzyme gave a single protein band with a molecular mass of 28 kDa on SDS-PAGE. The enzyme showed activity to various lipid hydroperoxides and their methyl esters. The enzyme was also active toward phosphatidylcholine hydroperoxide and cholesterol hydroperoxide. Since the enzyme was not active on hydrogen peroxide, the enzyme was thought to be a kind of glutathione S-transferase, although the purified enzyme did not show the glutathione-conjugating activity with electrophilic compounds such as 1-chloro-2,4-dinitrobenzene and o-dinitrobenzene, which are used as the substrate of glutathione S-transferase in yeast. The glutathione peroxidase in H. mrakii was then suggested to be a novel type of glutathione peroxidase in substrate specificity and intracellular localization, being different from those of other sources purified so far.
...
PMID:Oxidative stress response in yeast: purification and some properties of a membrane-bound glutathione peroxidase from Hansenula mrakii. 832 47

Female F344 rats received an i.p. injection of iron-dextran (600 mg Fe/kg) and then after 1 week were fed a diet containing 0.02% hexachlorobenzene (HCB) for up to 65 weeks. All rats (8/8) which received HCB after iron overload developed multiple hepatic nodules whereas only 3/8 rats administered HCB alone had nodules (average of one per positive liver). These hyperplastic regions were depleted of iron and were often positive for gamma-glutamyl transpeptidase (GGT) and glutathione S-transferase P (GST-P). Telangiectasis and peliosis were prominent features in the lesions. Short-term experiments (5-15 weeks of iron/HCB treatments) showed that GGT and GST-P were induced early in the neoplastic process but not in discrete focal areas. Iron alone also caused some induction of these enzymes. Some cells with induced GST-P in either short or long term experiments also stained positively for this enzyme in the nucleus. Studies of cytochrome P450 mediated activities showed that at 5 and 15 weeks HCB had induced EROD (an estimate of CYP1A1), PROD (CYP2B1 activity) and BROD activities (CYP2B1 but also other isoenzymes). Under the influence of iron overload EROD was significantly depressed from HCB alone, but not the others or cytochrome P450 reductase. Cytosolic glutathione S-transferase activities were also induced by HCB, but, unlike microsomal EROD, preloading with iron enhanced the effects. In contrast, although cytosolic diaphorase activity was induced by HCB, this response was depressed in combination with iron. Glutathione peroxidase (with H2O2 as substrate) was depressed by both iron and HCB. Clearly, iron overload potentiates the neoplastic process induced by HCB in rats, with both enhancing and depressing effects on various enzyme activities induced by this chemical.
...
PMID:Enhancement by iron of hepatic neoplasia in rats caused by hexachlorobenzene. 833 Mar 54

The effects of aging on the activities of drug-metabolizing enzymes and antioxidant enzymes were studied in male and female White-Footed mice (Peromyscus leucopus) at ages of 6, 8, 12, 18, 24, 30, 36, and 48 months. Male mice had significantly higher liver microsomal cytochrome P450 (P450) content and NADPH:cytochrome P450 oxidoreductase (P450 reductase) activities than females at all age groups. Many of the P450-dependent enzyme activities were also generally higher in males. Female mice showed age-dependent decreases in P450 content and the activities of P450 reductase, pentoxyresorufin O-dealkylase (PROD) and N-nitrosodimethylamine demethylase (NDMAd) in the liver from 6 to 24 months; while, the males showed an age-dependent decrease only for the liver PROD activity from 6 to 24 months. The old males (30-month old) appeared to have significantly higher activities for 6 beta-, 2 beta-, 16 alpha- and 16 beta-testosterone and androstenedione formation than the middle-aged (6- to 18-month old) and very old (48-month old) males. Females showed age-dependent decreases for the formation of 6 beta-, 2 beta-, 16 alpha- and 16 beta-testosterone in liver microsomes from 6 to 24 months. Lung microsomes from 6- and 8-month old males had much higher activities of ethoxyresorufin O-deethylase (EROD) and PROD than older males. The total NNK alpha-hydroxylation activities changed in the same pattern as lung microsomal EROD and PROD activities in both male and female mice. The activities of several phase II drug-metabolizing enzymes: glutathione S-transferase (GST), DT-diaphorase, sulfotransferase and UDP-glucuronosyl-transferase (UDPGT) did not show any significant age-dependent changes, with the possible exception that the GST activity in males decreased from 18 to 36 months. Males had about 3-fold higher UDPGT activities than females among all age groups. Glutathione peroxidase activities were drastically lower in old and very old males, and 6 to 24 months old males had significantly higher activities than the corresponding females. In females, superoxide dismutase activities decreased linearly to extremely low levels as mice aged. Catalase activities showed a tendency for increase with age in males. In conclusion, some P450-dependent activities and antioxidant enzymes, but not phase II drug-metabolizing enzymes, showed age-dependent changes; and most of these changes occur from 6 to 24 months. The demographic attributes of the White-Footed mouse are well-suited for physiological and biochemical studies of aging and can complement the more standard laboratory mouse model with its typical two year life span.
...
PMID:Age- and gender-related variations in the activities of drug-metabolizing and antioxidant enzymes in the white-footed mouse (Peromyscus leucopus). 849 97

Polychlorinated biphenyls are known to cause induction in cytochrome P450-dependent monooxygenase activities and alteration in the antioxidant defense of mammals. To determine whether similar detoxication processes are activated in rainbow trout (Oncorhynchus mykiss), we investigated P450-dependent enzyme activities, antioxidant enzymes and glutathione status (reduced and oxidized glutathione, GSH and GSSG) in this species injected intraperitoneally with 3,3',4,4'-tetrachlorobiphenyl at 5 mg/kg body weight 6 weeks post injection. Ethoxyresorufin O-deethylase activities increased 11- and 40-fold in liver and kidney. UDPglucuronosyltransferase activities were 2- and 5-fold higher in these organs, while glutathione S-transferase activity was enhanced greater than 2-fold in liver of tetrachlorobiphenyl injected trout in comparison with controls. Glutathione peroxidase activities were increased in liver and white muscle of dosed fish. Tetrachlorobiphenyl exposure resulted in a significant increase in glutathione reductase activities, with 7-fold enhancement in liver and significantly elevated activities in kidney, red and white muscles. Similarly, cytosolic superoxide dismutase and catalase activities were increased in white muscle of injected trout. Tetrachlorobiphenyl exposure significantly increased GSH concentrations in liver and kidney, while GSSG levels were increased in liver and blood plasma. These changes, however, did not modify the GSSG/GSH ratios in these tissues. Overall, these results imply a major tetrachlorobiphenyl effect on GSH status and antioxidant enzymes in trout tissues and identify white muscle along with liver and kidney as important tissues in the detoxication process in this animal.
...
PMID:3,3',4,4'-tetrachlorobiphenyl effects on antioxidant enzymes and glutathione status in different tissues of rainbow trout. 857 41

Levels of aldose reductase, glyoxalase I, and glyoxalase II in mononuclear and polymorphonuclear cells from insulin-dependent diabetes mellitus (IDDM) patients with long term diabetic complications were compared to levels in IDDM patients without complications and to those in nondiabetic controls. Cells were isolated from 22 asymptomatic long term IDDM patients, 22 symptomatic IDDM patients, and 16 controls, using a double gradient centrifugation procedure. Aldose reductase was determined by Western blots using polyclonal antiserum to human aldose reductase purified from skeletal muscle. Glyoxalase I and glyoxalase II were determined spectrophotometrically. Aldose reductase in mononuclear cells from symptomatic IDDM patients is significantly elevated compared to that in asymptomatic IDDM patients (mean +/- SEM, 0.96 +/- 0.20 vs. 0.46 +/- 0.08 microgram/mg protein; P < 0.02). Aldose reductase was not detected in polymorphonuclear cells. Glyoxalase I in mononuclear and polymorphonuclear cells from symptomatic IDDM patients is significantly elevated compared to that in controls [mean for mononuclear cells, 0.46 +/- 0.03 vs. 0.37 +/- 0.03 mumol/min.mg (P < 0.05); mean for polymorphonuclear cells, 0.16 +/- 0.01 vs. 0.10 +/- 0.01 mumol/min.mg (P < 0.002)]. Glyoxalase II is significantly elevated only in polymorphonuclear cells from symptomatic IDDM patients compared to controls (mean, 0.13 +/- 0.01 vs. 0.063 +/- 0.016 mumol/min.mg; P < 0.005). Glutathione peroxidase and glutathione S-transferase were not significantly different in these populations. Aldose reductase, glyoxalase I, and glyoxalase II are involved in the metabolism of methylglyoxal, suggesting that methylglyoxal may play a role in the etiology of diabetic complications.
...
PMID:Increased levels of methylglyoxal-metabolizing enzymes in mononuclear and polymorphonuclear cells from insulin-dependent diabetic patients with diabetic complications: aldose reductase, glyoxalase I, and glyoxalase II--a clinical research center study. 863 55

The effect of repeated exposures to N, N-dimethylformamide (DMF) on the liver and the hepatic microsomal monooxygenase system and glutathione metabolizing enzymes were investigated. DMF was administered to Wistar male rats by subcutaneous (s.c.) injection at 1.0 ml/kg body weight (950 mg/kg), 3 times a week for 2 weeks. The gain in the body weight in the DMF group were suppressed compared with the control group at 2 week. The relative weight of the liver, spleen and kidney also appeared to increase in the DMF group as same as in the control group. Hematological examinations showed no changes. Glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) did not change in the DMF group. Hepatic microsomal protein and cytochrome P-450 did significantly decrease by 30% and 38%, respectively, while there was no change in cytochrome b5, NADPH-cytochrome c reductase and NADH-ferricyanide reductase. Glutathione peroxidase (GPx) activity was not affected by DMF administration, while glutathione reductase (GR) and glutathione S-transferase, (GST) activity were significantly increased by 16% and 64%, respectively. These results indicate that DMF alters tke hepatic drug metabolizing system without significant increase of the serum transaminase levels. These findings may contribute to elucidate the mechanism of DMF hepatotoxicity.
...
PMID:Alterations of hepatic drug metabolising system due to dimethylformamide (DMF). 877 55

Liver lipid peroxidation, nonheme iron, antioxidants, and protein oxidation were investigated in experimental alcohol-induced liver disease in the rat. Wistar male rats were intragastrically and continuously infused for 4 weeks with a high-fat diet plus an ethanol or an isocaloric amount of dextrose, maintaining a high blood alcohol level (200-300 mg%). This model induced fatty liver, spotty necrosis, and focal inflammation. This pathology was associated with an enhanced lipid peroxidation and a decrease in the major antioxidant factors. Hepatic alpha-tocopherol and glutathione concentrations were significantly decreased in ethanol-fed rats. Glutathione peroxidase (GPx) was also decreased, whereas glutathione S-transferase (GST) was unaffected. The nonheme iron level was significantly decreased. Protein oxidation was assessed through three parameters: protein thiols, protein carbonyl groups, and the activity of glutamine synthetase (GS), a centrilobular enzyme particularly susceptible to free-radical-mediated damage. Ethanol-fed rats had decreased protein thiol concentrations and reduced GS activity, together with increased protein carbonyls. A significant correlation between GS activity and the pathological score was observed. This study confirms the ethanol-related increase in lipid peroxidation and shows that ethanol impairs the hepatic antioxidant potential. Furthermore, evidence of oxidative protein damage is given, including decreased activity of a key enzyme of ammonia metabolism. These protein disturbances may contribute to the pathogenesis of the observed liver damage.
...
PMID:Effect of chronic ethanol feeding on lipid peroxidation and protein oxidation in relation to liver pathology. 902 46


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

---