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Query: UMLS:C0022116 (ischemia)
91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activity of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase as well as content of diene conjugates and malonic dialdehyde were studied in blood serum and cerebrospinal fluid of patients with transitory ischemia, small ischemic insult, ischemic insult of middle severity and with severe ischemic insult without lethality within 1-2, 7-8 and 14-15 days of diseases. Content of lipid peroxidation products and activity of antioxidant enzymes were decreased in the biological fluids studied in all the forms of brain circulation impairments within early periods of pathology. These patterns tend to normalization within 14-15 days. The rate of biochemical alterations corresponded highly to severity of impairments developed and these patterns may be used for diagnostic and prognostic purposes.
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PMID:[Activity of antioxidant protection enzymes and content of lipid peroxidation products in blood serum and cerebrospinal fluid in patients with ischemic brain disease]. 141 27

The isolated blood-perfused rabbit heart, subjected to 60 min of cardioplegic arrest and 60 min of reperfusion, was used to assess the effects of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) on postischemic recovery of left ventricular developed pressure (LVDP), the tissue activity of SOD, and tissue redox state. The five groups studied were the following: PEG-SOD-free control (group A), PEG-SOD as a pretreatment and as an additive during cardioplegia and reperfusion (group B), PEG-SOD as a pretreatment and a cardioplegic additive (group C), PEG-SOD in cardioplegia alone (group D), and PEG-SOD in reperfusion alone (group E). The results show that pretreatment with PEG-SOD improves postischemic recovery of LVDP (72 +/- 2% and 66 +/- 7 vs. 47 +/- 4% in groups B, C, and A, respectively). This protection was associated with an improved tissue redox state. Thus the ischemia-induced rise in oxidized glutathione was reduced from 313 +/- 26% (group A) to 162 +/- 15 and 138 +/- 14% (groups B and C, respectively), and the fall in reduced glutathione was attenuated from 51 +/- 5% to 35 +/- 6 and 13 +/- 5%, respectively. Tissue Mn-SOD activity was also conserved from 36 +/- 4% (group A) to 71 +/- 6 and 94 +/- 4% (groups B and C, respectively). No significant effect was seen when PEG-SOD was applied in cardioplegia or during reperfusion alone.
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PMID:PEG-SOD improves postischemic functional recovery and antioxidant status in blood-perfused rabbit hearts. 141 72

Peroxynitrite (ONOO-), the reaction product of superoxide (O2-) and nitric oxide (NO), may be a major cytotoxic agent produced during inflammation, sepsis, and ischemia/reperfusion. Bovine Cu,Zn superoxide dismutase reacted with peroxynitrite to form a stable yellow protein-bound adduct identified as nitrotyrosine. The uv-visible spectrum of the peroxynitrite-modified superoxide dismutase was highly pH dependent, exhibiting a peak at 438 nm at alkaline pH that shifts to 356 nm at acidic pH. An equivalent uv-visible spectrum was obtained by Cu,Zn superoxide dismutase treated with tetranitromethane. The Raman spectrum of authentic nitrotyrosine was contained in the spectrum of peroxynitrite-modified Cu,Zn superoxide dismutase. The reaction was specific for peroxynitrite because no significant amounts of nitrotyrosine were formed with nitric oxide (NO), nitrogen dioxide (NO2), nitrite (NO2-), or nitrate (NO3-). Removal of the copper from the Cu,Zn superoxide dismutase prevented formation of nitrotyrosine by peroxynitrite. The mechanism appears to involve peroxynitrite initially reacting with the active site copper to form an intermediate with the reactivity of nitronium ion (NO2+), which then nitrates tyrosine on a second molecule of superoxide dismutase. In the absence of exogenous phenolics, the rate of nitration of tyrosine followed second-order kinetics with respect to Cu,Zn superoxide dismutase concentration, proceeding at a rate of 1.0 +/- 0.1 M-1.s-1. Peroxynitrite-mediated nitration of tyrosine was also observed with the Mn and Fe superoxide dismutases as well as other copper-containing proteins.
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PMID:Peroxynitrite-mediated tyrosine nitration catalyzed by superoxide dismutase. 141 74

A prostaglandin I2 (PGI2) analogue and superoxide dismutase (SOD) were administered to dogs with pulmonary denervation, and their effects on warm ischemic damage to the lung were studied. Twenty-seven adult mongrel dogs were divided into a control group (6 dogs), a PGI2 group (7 dogs), an SOD group (6 dogs), and a heparin group (8 dogs). The left pulmonary hilum was dissected, with PGI2 (1 microgram/kg) being administered to the PGI2 group and heparin (100 U/kg) to the heparin group. Then the left lung was placed in a warm ischemic state for 1 hour. The SOD group also received 20 mg/kg of SOD intravenously 1 minute before reperfusion. Before warm ischemia, immediately after reperfusion, and 1 hour and 2 hours afterward, the blood gases, left pulmonary vascular resistance, and other data were measured under right pulmonary artery clamping. Arterial oxygen tension showed significantly better values in the SOD and PGI2 groups than in the control and heparin groups. The left pulmonary vascular resistance increased with time in the control group but did not increase in the PGI2 group. Pulmonary microangiography showed that dilatation of the pulmonary arterioles was prominent in the PGI2 group. The quantity of pulmonary extravascular fluid was significantly less in the PGI2 and SOD groups than in the control and heparin groups. Histological examination showed marked collapse of capillaries, intraalveolar hemorrhage, and edema in the control and heparin groups, whereas these changes were only slight in the PGI2 and SOD groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of prostaglandin I2 and superoxide dismutase on reperfusion injury of warm ischemic lung. 141 87

Although a lot of investigations indicated that free radical scavengers, such as superoxide dismutase (SOD) and catalase, reduced ischemia-reperfusion injury, the precise mechanism including the sites of action are still controversial. The purposes of this study were to investigate the sites of action of SOD and catalase by assessing postischemic cardiac and endothelial cell function. Wistar rats (450-550g) were used as support animals to establish blood perfused circuit. A peristaltic pump controlled the femoral arterial supply at 3.0 ml/min and the venous return to the jugular vein with gravity. Hearts (n = 8/group) from the Wistar rats were perfused (Langendorff model) and paced at 350 beats/min. After assessing baseline functions, hearts were rendered ischemia at 37.5 degrees C for 20 min. Then hearts were reperfused for 35 min, at the end of which left ventricular functions were re-assessed. One group of hearts received a continuous infusion of SOD and catalase during the period of 10 min before ischemia to 20 min after the onset of reperfusion. Left ventricular functions were measured with a left intraventricular balloon. The end-diastolic pressure was fixed at 10 mmHg, which was equivalent to the normal left ventricular end-diastolic pressure. The mean postischemic recovery of the left ventricular end-systolic pressure was increased from 55 +/- 3% in the control group to 67 +/- 2% in the SOD and catalase group (P less than 0.05). Similarly, the postischemic compliance was increased from 1.28 +/- 0.12 (microliters/mmHg) in the control group to 1.61 +/- 0.11 (microliters/mmHg) in the SOD and catalase group (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The effect of oxygen free radical scavenger on endothelial cell at ischemic and reperfusion injury]. 142 95

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.
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PMID:Antioxidant enzymes in the differentiated Caco-2 cell line. 142 66

We have previously shown that the polyethylene glycol conjugated superoxide dismutase (SOD), which has a plasma half-life of more than 24 h, protects the blood perfused rabbit heart against injury during ischaemia and reperfusion. However, the profile for the dose-dependency of protection was bell-shaped with loss of efficacy below 6000 and above 30,000 U/kg. In the present study, isolated rabbit hearts, perfused with blood from support rabbits, were subjected to a 2 min infusion with St Thomas' Hospital cardioplegic solution followed by 60 min of global ischaemia (37 degrees C) and 60 min of reperfusion. PEG-SOD was administered 1 h or 12-24 h before ischaemia. We assessed the effect of PEG-SOD on ischaemia- and reperfusion-induced changes in: (i) the tissue content of reduced glutathione (GSH), oxidized glutathione (GSSG) and malondialdehyde (MDA) and (ii) the activity of CuZn-SOD, Mn-SOD and glutathione peroxidase and reductase (GPD and GRD). Ischaemia and reperfusion reduced tissue GSH content by 70% and increased GSSG content by 400% (from their fresh aerobic values of 13.1.9 and 0.09 +/- 0.01 nmol/mg protein, respectively). PEG-SOD, given intravenously at various doses to donor and support rabbits 1 h or 12-24 h before ischaemia, protected against these changes with a bell-shaped dose-response relationship. Thus, with 0, 3000, 6000, 12,000, 30,000 and 60,000 U/kg, GSH content was 4.1 +/- 0.4, 4.8 +/- 0.4, 8.5 +/- 0.5, 12.3 +/- 1.6, 12.3 +/- 1.6 and 5.0 +/- 0.5 nmol/mg protein in the 1 h pretreatment group and 4.1 +/- 0.4, 4.2 +/- 0.5, 10.4 +/- 1.5, 11.2 +/- 1.1, 11.4 +/- 0.7 and 4.7 +/- 0.6 nmol/mg protein in the 12-24 h pretreatment group (means +/- S.E.M.). For GSSG the corresponding values were 0.36 +/- 0.04, 0.34 +/- 0.03, 0.12 +/- 0.01, 0.12 +/- 0.01, 0.11 +/- 0.01 and 0.41 +/- 0.03 nmol/mg protein for the 1 h group and 0.36 +/- 0.04, 0.35 +/- 0.02, 0.15 +/- 0.01, 0.12 +/- 0.01, 0.11 +/- 0.01 and 0.34 +/- 0.02 nmol/mg protein for the 12-24 h group. Ischaemia and reperfusion had no effect on tissue MDA content or CuZn-SOD, GDP and GRD activity, and in general, PEG-SOD also lacked significant effect on any of these variables at any dose studied. However, Mn-SOD activity was severely reduced by ischaemia and reperfusion (from 42 +/- 7 U/mg protein in fresh aerobic controls to 6 +/- 1 U/mg protein at the end of reperfusion).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:PEG-SOD and myocardial antioxidant status during ischaemia and reperfusion: dose-response studies in the isolated blood perfused rabbit heart. 143 18

Various methods have been used in the past to assess the implication of oxygen free radicals (OFR) in ischemia-reperfusion-induced cardiac injury. Luminol-enhanced tert-butyl-initiated chemiluminescence in cardiac tissue reflects oxidative stress and is a very sensitive method. It was used to elucidate the role of OFR in cardiac injury due to ischemia and reperfusion. Studies were conducted on perfused isolated rabbit hearts in three groups (n = 8 in each): I, control; II, submitted to global ischemia for 30 min; III, submitted to ischemia for 30 min followed by reperfusion for 60 min. The heart tissue was then assayed for chemiluminescence (CL); content of malondialdehyde (MDA), an indicator of OFR-induced cardiac injury; and activity of tissue levels of antioxidants [superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px)]. The control values for left and right ventricular CL and malondialdehyde were 81.1 +/- 15.4 (S.E.) and 182.4 +/- 50.3 (S.E.), mv.min.mg protein-1; and 0.024 +/- 0.006 (S.E.) and 0.324 +/- 0.005 (S.E.) nmoles.mg protein-1 respectively. Ischemia produced an increase in the cardiac CL (3.3 to 4.4 fold) and MDA content (2 to 2.6 fold). Reperfusion following ischemia also produced similar changes in CL and MDA content. The control values for activity of left ventricular SOD, catalase, and GSH-Px were 45.77 +/- 1.73 (S.E.) U.mg protein-1, 5.35 +/- 0.51 (S.E.) K.10(-3).sec-1.mg protein-1, and 77.50 +/- 7.70 (S.E.) nmoles NADPH.min-1.mg protein-1 respectively. Activities of SOD and catalase decreased during ischemia but were similar to control values in ischemic-reperfused hearts. The GSH-Px activity of left ventricle was unaffected by ischemia, and ischemia-reperfusion. GSH-Px activity of the right ventricle increased with ischemia, and ischemic-reperfusion. These results indicate that cardiac tissue chemiluminescence would be a useful and sensitive tool for the detection of oxygen free radical-induced cardiac injury.
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PMID:Detection of ischemia-reperfusion cardiac injury by cardiac muscle chemiluminescence. 143 65

Intravenous administration of xanthine (X: 0.225 mg/kg, i.v.) plus xanthine oxidase (XO: 3.0 units/kg, i.v.) to anesthetized rats resulted in a rapid fall in the arterial pressure and a mortality rate of over 80% during 120 min observation period. Pretreatment of the rats with superoxide dismutase (SOD) or SOD plus catalase significantly enhanced survival rate to 60% confirming that the toxicity after [X + XO] administration is due to the generation of oxygen free radicals. Pretreatment of the rats with either felodipine, a dihydropyridine calcium antagonist or verapamil, a structurally different Ca(2+)-channel blocker was most effective in promoting survival rate to 90%; in contrast, hydralazine, an arteriolar dilator but not a calcium antagonist, was ineffective in significantly enhancing survival. In the vehicle treated groups, mortality of the rats after [X + XO] administration was associated with significant increases in serum creatine phosphokinase (CPK) levels; both the calcium antagonists as well as hydralazine prevented any significant changes in CPK levels. Since only the calcium antagonists but not hydralazine were effective in providing significant protection against mortality, the data suggests that CPK may not be a reliable indicator to predict prevention of lethal toxicity induced by free radicals. Hence, the observation that calcium antagonists can promote survival would suggest that calcium overload may be the ultimate mediator of tissue toxicity. These observations can account for the remarkable efficacy of various calcium antagonists in preventing ischemia-reperfusion induced damage to organs, such as heart and kidneys, in which a role for free radicals has been postulated.
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PMID:Evaluation of the effects of felodipine, verapamil and hydralazine on the survival rate of rats subjected to lethal effects of oxygen free radicals. 143 30

Therapeutic effects of four types of recombinant superoxide dismutase (SOD) derivatives, conjugates with polysaccharides, carboxymethyl (SOD-CMD) and diethylaminoethyl (SOD-DEAED) dextrans and galactosylated (Gal-SOD) and mannosylated (Man-SOD) derivatives, on hepatic ischemia/reperfusion injury were studied in rats. Hepatic injury induced by transient occlusion and subsequent reflow of hepatic blood was evaluated by the analysis of biliary excretion of bromosulfophthalein (BSP) injected intravenously. At a dose of 10000 units/kg, native SOD and SOD-DEAE did not show any significant effect and SOD-CMD showed slight effect. On the other hand, Gal-SOD and Man-SOD, targeted to the liver parenchymal and nonparenchymal cells, respectively, by a receptor-mediated endocytosis, exhibited superior inhibitory effects. These results demonstrated that these glycosylated SOD derivatives were useful for the prevention of hepatic ischemia/reperfusion injury.
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PMID:Therapeutic effects of superoxide dismutase derivatives modified with mono- or polysaccharides on hepatic injury induced by ischemia/reperfusion. 144 73


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