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Query: UMLS:C0042373 (vascular disease)
 17,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxidative damage due to free radical production is increased in uraemic patients and has been suggested as a possible factor contributing to the anaemia of chronic renal failure (CRF) and the pathogenesis of atherosclerosis. Oxidative stress was assessed in 40 patients with CRF maintained by either haemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) and in 18 healthy controls. Lipid peroxidation (assessed as malondialdehyde, MDA), total glutathione (TG), antioxidant enzyme (glutathione reductase (GSHRx), glutathione peroxidase (GSHPx) and superoxide dismutase (SOD)) activity and antioxidant associated trace metal (selenium, copper, zinc) levels were studied. Erythrocyte membrane fluidity was examined using the fluorescent probe 1,6 diphenyl-1,3,5-hexatriene (DPH). The results indicate increased levels of oxidative stress and altered erythrocyte membrane fluidity in patients treated with CAPD compared with controls and patients treated with HD. Only minor changes were observed in patients treated with HD. Altered free radical activity, oxidative stress and altered erythrocyte membrane fluidity observed in patients with CRF may contribute to the increase in vascular disease in such patients and to the anaemia of CRF.
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PMID:Oxidative stress and erythrocyte membrane fluidity in patients undergoing regular dialysis. 755 72

The relationship between antioxidants and endothelial cell injury was examined in 119 patients with (n = 48) or without (n = 71) vascular disease who were attending a hyperlipidaemia clinic. Serum levels of total antioxidant capacity, glutathione peroxidase (a protein antioxidant), von Willebrand factor (vWf, a specific endothelial cell product and marker of injury) and routine lipids were measured in the patients and from 58 healthy controls. Compared to controls, total antioxidant capacity (P < 0.01) and glutathione peroxidase (P < 0.0001) were lower whilst vWf was higher (P < 0.0001) amongst the patients. Comparing patients with and without vascular disease, glutathione peroxidase was lower (P < 0.03) and vWf was higher (P < 0.05) in the presence of vascular disease but there was no difference in levels of serum lipids or total antioxidant capacity. vWf and glutathione peroxidase were inversely correlated (r = -0.26, P < 0.005). We conclude that patients with hypercholesterolaemia have reduced antioxidant capacity and this is most severe in patients with clinically apparent vascular disease. This, linked to the finding of increased vWf in hypercholesterolaemia with highest levels in those patients with vascular disease, suggests that loss of antioxidant capacity may expose the vascular endothelium to excess oxidative damage. These results suggest a link between hypercholesterolaemia, impaired ability to resist free radical attack, and the development of atherosclerosis.
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PMID:Antioxidants, von Willebrand factor and endothelial cell injury in hypercholesterolaemia and vascular disease. 757 74

The study included 16 patients with diabetes mellitus (DM) type 1 and 15 healthy controls. By the moment of examination the patients had achieved subcompensation. 10 patients developed diabetic vascular complications. The patients received biosynthetic insulins Humulin S, Humulin I, Humulin M3. Pretreatment glycemia in the patients surpassed that in the controls, MDA red cell levels per ml of hemolysate were higher by 121% and 130% per protein 1 mg. MDA measured equal both in angiopathy patients and those without it. The activity of the antioxidant enzymes in DM patients was similar to control indices. Human insulin administration reduced red cell MDA levels both in angiopathy and free of it patients, though in the former MDA remained higher than normal, while in the latter normal levels are obtained. The parameters of the antioxidant defense enzymes changed on the treatment week 12: catalase activity rose by 41%, that of superoxide dismutase and glutathione peroxidase lowered by 35 and 65%, respectively. Variations in these enzymes activity showed no dependence on vascular complications.
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PMID:[Lipid peroxidation and the antioxidant protection of the erythrocytes in diabetes mellitus patients]. 829 27

Increase in lipid peroxidation (LP) is an indirect marker of free radical activation. The products of LP (malonyldialdehyde: MDA) are increased in diabetic patients, particularly those with angiopathy. Free radicals are eliminated by cellular enzymes such as superoxide dismutase, catalase and glutathione peroxidase. In this study, the effect and the mechanism of action of captopril, and angiotensin converting enzyme (ACE) inhibitor, on lipid peroxidation in erythrocytes from diabetics was investigated. LP and glutathione were studied in 10 type II diabetics (mean age: 57 +/- 10 yr, duration of diabetes: 12 +/- 6 yr) and in 10 healthy subjects (mean age: 30 +/- 5 yr). Lipid peroxidation levels were 20.69 +/- 4.68 MDA% in diabetics and 9.62 +/- 1.87 MDA% in normal subjects. The LP in erythrocytes of type II diabetics was decreased by the increasing concentrations of captopril (before captopril: 20.69 +/- 4.68, after captopril: (2 x 10(-5) M) 16.68 +/- 7.49 MDA%; (4 x 10(-5) M) 14.17 +/- 7.65 MDA%; (6 x 10(-5) M) 12.33 +/- 2.8 MDA%). No difference was found in the inhibition of LP between the captopril concentrations of 6 x 10(-5) M and 10 x 10(-5) M. After preincubation with captopril, the glutathione level did not change significantly in the diabetic and normal erythrocytes. Preincubation with 2-6 x 10(-5) M captopril showed no effect in the normal group (p > 0.05) but 10 x 10(-5) M captopril reduced lipid peroxidation (p < 0.01). In our study, the high levels of lipid peroxidation in erythrocytes from diabetic patients were decreased after preincubation with captopril. Decrease in the level of lipid peroxidation in vitro was independent of the glutathione level. Crosslink binding between MDA and captopril is suggested.
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PMID:The in vitro effects of captopril on the levels of lipid peroxidation and glutathione of erythrocytes in type II diabetes. 885 73

Oxidant stress is believed to be enhanced in patients with diabetes mellitus, which may lead to endothelial dysfunction and the development of atherosclerosis. In diabetes, hyperglycemia drives non-enzymatic glycation and oxidation of proteins and lipids which enhances the formation of advanced glycation end products (AGEs), which may be involved in the pathogenesis of diabetic vascular disease. The macrovascular complications of diabetes seem to be due to enhanced cellular oxidant stress by the interaction of AGEs with their receptor. It would be worthwhile to devise methods to reduce this oxidant stress. In alloxan-induced diabetic rats lipid peroxidation products were increased, while levels of nitric oxide glutathione peroxidase and superoxide dismutase were reduced. Melatonin restored these biochemical abnormalities to normalcy independent of hyperglycemia. This model can be used to study the role of oxidant stress in the development of macrovascular complications in diabetes mellitus.
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PMID:Preservation of the antioxidant status in chemically-induced diabetes mellitus by melatonin. 1098 24

Vascular disease and vasomotor responses are largely influenced by oxidant stress. Superoxide is generated via the cellular oxidase systems, xanthine oxidase, and NADH/NADPH oxidases. Once formed, superoxides participate in a number of reactions, yielding various free radicals such as hydrogen peroxide, peroxynitrite, oxidized low-density lipoprotein, or hypochlorous acid. Numerous cellular antioxidant systems exist to defend against oxidant stress; glutathione and the enzymes superoxide dismutase and glutathione peroxidase are critical for maintaining the redox balance of the cell. However, the redox state is disrupted by certain vascular diseases. It appears that oxidant stress both promotes and is induced by diseases such as hypertension, atherosclerosis, and restenosis as well as by certain risk factors for coronary artery disease including hyperlipidemia, diabetes, and cigarette smoking. Once oxidant stress is invoked, characteristic pathophysiologic features ensue, namely adverse vessel reactivity, vascular smooth muscle cell proliferation, macrophage adhesion, platelet activation, and lipid peroxidation.
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PMID:Oxidant stress in the vasculature. 1112 5

Elevated plasma homocysteine is a new risk factor for atherosclerotic vascular disease resulting in progressive atherogenesis in the arteries of the limbs, the coronary arteries and the cerebrovascular system. Hyperhomocysteinemia may be induced by failure or decreased enzyme activity of the cystathionine-beta-synthase and methylenetetrahydrofolate reductase due to genetic mutation or deficiency of folic acid, vitamin B12 and vitamin B6. Oxidation of homocysteine to homocystine is accompanied with production of hydrogen peroxide inducing damage of endothelium through oxidative stress. The injury of the endothelium by homocysteine can be shown by measuring flow-induced vasodilation in men. The abnormalities of coagulation found in hyperhomocysteinemia is related to the impairment of the function of endothelial cells and inhibition of the thrombomodulin-protein C and glycosaminoglycan-antithrombin-III anticoagulant system. Homocysteine decreases the level of glutathione peroxidase in the endothelial cells, and inhibits its activation leading to the impairment of oxidative defensive mechanism, and to the free radical-induced NO-inactivation. In decreasing of plasma homocysteine level and preventing its influence on endothelium, moreover in improving of endothelial function the folic acid has cardinal importance, however the vitamin B12 and vitamin B6 also play role in the maintenance of normal homocysteine level of blood.
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PMID:[Homocysteine--a risk factor for atherosclerosis]. 1148 6

Human umbilical vein endothelial cells (HUVECs) are an endothelial model of replicative senescence. Oxidative stress, possibly due to dysfunctional mitochondria, is believed to play a key role in replicative senescence and atherosclerosis, an age-related vascular disease. In this study, we determined the effect of cell division on genomic instability, mitochondrial function, and redox status in HUVECs that were able to replicate for approximately 60 cumulative population doublings (CPD). After 20 CPD, the nuclear genome deteriorated and the protein content of the cell population increased. This indicated an increase in cell size, which was accompanied by an increase in oxygen consumption, ATP production, and mitochondrial genome copy number and approximately 10% increase in mitochondrial mass. The antioxidant capacity increased, as seen by an increase in reduced glutathione, glutathione peroxidase, GSSG reductase, and glucose-6-phosphate dehydrogenase. However, by CPD 52, the latter two enzymes decreased, as well as the ratio of mitochondrial-to-nuclear genome copies, the mitochondrial mass, and the oxygen consumption per milligram of protein. Our results signify that HUVECs maintain a highly reducing (GSH) environment as they replicate despite genomic instability and loss of mitochondrial function.
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PMID:Endothelial cells maintain a reduced redox environment even as mitochondrial function declines. 1238 90

We report here that estrogen (E(2)) modulates mitochondrial function in the vasculature. Mitochondrial dysfunction is implicated in the etiology of vascular disease; thus, vasoprotection by estrogen may involve hormonal effects on the mitochondria. To test this hypothesis, mitochondria were isolated from cerebral blood vessels obtained from ovariectomized female rats, with or without E(2) replacement. Estrogen receptor-alpha (ER-alpha) was detected in mitochondria by immunoblot and confocal imaging of intact vessels. E(2) treatment in vivo increased the levels of specific proteins in cerebrovascular mitochondria, such as ER-alpha, cytochrome c, subunit IV of complex IV, and manganese superoxide dismutase, all encoded in the nuclear genome, and subunit I of complex IV, encoded in the mitochondrial genome. Levels of glutathione peroxidase-1 and catalase, however, were not affected. Functional assays of mitochondrial citrate synthase and complex IV, key rate-limiting steps in energy production, showed that E(2) treatment increased enzyme activity. In contrast, mitochondrial production of hydrogen peroxide was decreased in vessels from E(2)-treated animals. In vitro incubation of cerebral vessels with 10 nM 17beta-estradiol for 18 h also elevated levels of mitochondrial cytochrome c. This effect was blocked by the estrogen receptor antagonist fulvestrant (ICI-182,780, Faslodex) but was unaffected by inhibitors of nitric-oxide synthase or phosphoinositide-3-kinase. Nuclear respiratory factor-1 protein, a primary regulator of nuclear gene-encoded mitochondrial genes, was significantly increased by long-term estrogen treatment in vivo. In summary, these novel findings suggest that vascular protection by E(2) is mediated, in part, by modulation of mitochondrial function, resulting in greater energy-producing capacity and decreased reactive oxygen species production.
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PMID:Estrogen increases mitochondrial efficiency and reduces oxidative stress in cerebral blood vessels. 1599 67

Several vascular disease are characterized by elevated levels of reactive oxygen species (ROS). Vascular endothelium is protected from oxidant stress by expressing enzymes such as glutathione peroxidase type 1 (GPx-1). In this study, we investigated the effect of vascular oxidant stress on ischemia-induced neovascularization in a murine model of homozygous deficiency of GPx-1. GPx-1-deficient mice showed impaired revascularization following hindlimb ischemic surgery based on laser Doppler measurements of blood flow and capillary density in adductor muscle. GPx-1-deficient mice also showed an impaired ability to increase endothelial progenitor cell (EPC) levels in response to ischemic injury or subcutaneous administration of vascular endothelial growth factor protein. EPCs isolated from GPx-1-deficient mice showed a reduced ability to neutralize oxidative stress in vitro, which was associated with impaired migration toward vascular endothelial growth factor and increased sensitivity to ROS-induced apoptosis. EPCs isolated from GPx-1-deficient mice were impaired in their ability to promote angiogenesis in wild-type mice, whereas wild-type EPCs were effective in stimulating angiogenesis in GPx-1-deficient mice. These data suggest that EPC dysfunction is a mechanism by which elevated levels of ROS can contribute to vascular disease.
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PMID:Impaired angiogenesis in glutathione peroxidase-1-deficient mice is associated with endothelial progenitor cell dysfunction. 1645 4


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