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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of 17beta-estradiol (17beta-E(2)) or the phytoestrogen naringenin on spontaneous atherosclerosis were studied in 36 ovariectomized homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits receiving a semisynthetic control diet; this diet added 0.0040% 17beta-E(2;) or 0.20% naringenin, for 16 weeks. The uterine weight was increased (P < 0.001) and the concentration of estrogen receptor alpha was decreased (P < 0.001) in the 17beta-E(2) group compared with the controls. Total plasma cholesterol and triglycerides were not different from those in the controls. In lipoproteins, HDL cholesterol was increased (P < 0.01), and LDL triglyceride and IDL triglyceride were lowered (P < 0.05). The oxidation (as concentration of malondialdehyde) was increased in LDL (P < 0.05) but not in plasma. The cholesterol accumulation was decreased (P < 0.05) in the ascending aorta and in the total aorta but the ratio of intima to media and area of intima in ascending, thoracic, and abdominal aorta were not significantly different. In the naringenin group the only differences, compared with the control group, were increased HDL cholesterol (P < 0.001) and decreased activity of glutathione reductase (P < 0.05). In conclusion, 17beta-E(2), but not naringenin, attenuated aortic cholesterol accumulation independently of plasma and LDL cholesterol. Further, these results support previously suggested pro-oxidant ability of 17beta-E(2) toward LDL and a possible connection between the pro-oxidant nature of 17beta-E(2) and its antiatherogenic effect.
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PMID:17beta-Estradiol but not the phytoestrogen naringenin attenuates aortic cholesterol accumulation in WHHL rabbits. 1135 91

Endogenous oxygen- and nitrogen-centered free radicals are considered to play a decisive role in a variety of diseases such as neurodegenerative disorders, atherosclerosis, or cancer. Directly operating antioxidants limit the action of freely diffusing radicals by scavenging the attacking, oxidizing radical and re-reducing the oxidized biomolecule, i.e., the biomolecule-derived radical. From textbooks of biochemistry it is understood that NAD(P)H acts as a hydride (hydrogen anion) donor in a variety of enzymatic processes. One example is the re-reduction of GSSG to GSH, catalyzed by glutathione reductase. Because of this reaction, NADPH has been suggested to also act as an indirectly operating antioxidant, thus maintaining the antioxidative power of glutathione. To the best of our knowledge, however, neither NADPH nor NADH has been considered to be directly operating antioxidants. Based on recently published data, new experiments, and theoretical considerations, we propose that NAD(P)H represents a decisive, directly operating antioxidant that should be considered of major importance in the mitochondrial compartment. NAD(P)H fulfills this task both by scavenging toxic free radicals and repairing biomolecule-derived radicals.
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PMID:NAD(P)H, a directly operating antioxidant? 1142 89

To compare the chronic effect of several dialytic techniques (bicarbonate dialysis, BHD; acetate free biofiltration, AFB; hemodiafiltration, HDF; paired filtration dialysis, PFD) on atherosclerosis and antioxidant activity, three different indices were created. The first (atherosclerotic index = AI) is formed using the sum of three plasma substances: MDA, Hcy, and Cys (malondialdehyde, homocysteine, cysteine). The second (antioxidant activity index = AOAI) is the sum of five erythrocyte (E) parameters: E-GSH, GPx, CAT, SOD, GR (E-glutathione, E-glutathione peroxidase, E-catalase, E-superoxide dismutase, E-glutathione reductase). The third (defense index = DI) is derived from the previous two: (AOAI - AI). The indices were so expressed as AI in mmol/L, AOAI in U/g hemoglobin (Hb), and DI in arbitrary units. These indices were calculated in 20 controls and 51 chronic HD patients (26 female, 25 male) before, during, and after the first session of the week. HD patients were divided according to their dialytic technique: BHD, n = 35; AFB, n = 5 patients; HDF, n = 7 patients; or PFD = 4 patients. All patients had been treated with a given technique for at least 12 months, before entering the study. As expected, HD patients had AI values higher than controls, both before and after the session, with a mean value of 541 (before) and 331 (after), whereas controls had a mean value of 205. The AOAI was lower than controls, both before and after the session, the mean value being 1,122 (before) and 1,582 (after), that of controls being 2,424. In all cases, PFD gave the best "acute" results; at the end of a PFD session, near normal values of AI, AOAI, and DI (defensive index = AOAI - AI) were obtained.
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PMID:Do different dialytic techniques have different atherosclerotic and antioxidant activities? 1157 29

Extensive evidence suggests that reactive oxygen species are critically involved in the pathogenesis of cardiovascular diseases, such as atherosclerosis and myocardial ischemia-reperfusion injury. Consistent with this concept, administration of exogenous antioxidants has been shown to be protective against oxidative cardiovascular injury. However, whether induction of endogenous antioxidants by chemical inducers in vasculature also affords protection against oxidative vascular cell injury has not been extensively investigated. In this study, using rat aortic smooth muscle A10 cells as an in vitro system, we have studied the induction of cellular antioxidants by the unique chemoprotector, 3H-1,2-dithiole-3-thione [corrected] (D3T) and the protective effects of the D3T-induced cellular antioxidants against oxidative cell injury. Incubation of A10 cells with micromolar concentrations of D3T for 24 h resulted in a significant induction of a battery of cellular antioxidants in a concentration-dependent manner. These included reduced glutathione (GSH), GSH peroxidase, GSSG reductase, GSH S-transferase, superoxide dismutase, and catalase. To further examine the protective effects of the induced endogenous antioxidants against oxidative cell injury, A10 cells were pretreated with D3T and then exposed to either xanthine oxidase (XO)/xanthine, 4-hydroxynonenal, or cadmium. We observed that D3T pretreatment of A10 cells led to significant protection against the cytotoxicity induced by XO/xanthine, 4-hydroxynonenal or cadmium, as determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium reduction assay. Taken together, this study demonstrates for the first time that a number of endogenous antioxidants in vascular smooth muscle cells can be induced by exposure to D3T, and that this chemical induction of cellular antioxidants is accompanied by markedly increased resistance to oxidative vascular cell injury.
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PMID:Chemical induction of cellular antioxidants affords marked protection against oxidative injury in vascular smooth muscle cells. 1189 Jun 70

Radiation hazards in outer space present an enormous challenge for the biological safety of astronauts. A deleterious effect of radiation is the production of reactive oxygen species, which result in damage to biomolecules (e.g., lipid, protein, amino acids, and DNA). Understanding free radical biology is necessary for designing an optimal nutritional countermeasure against space radiation-induced cytotoxicity. Free radicals (e.g., superoxide, nitric oxide, and hydroxyl radicals) and other reactive species (e.g., hydrogen peroxide, peroxynitrite, and hypochlorous acid) are produced in the body, primarily as a result of aerobic metabolism. Antioxidants (e.g., glutathione, arginine, citrulline, taurine, creatine, selenium, zinc, vitamin E, vitamin C, vitamin A, and tea polyphenols) and antioxidant enzymes (e.g., superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidases) exert synergistic actions in scavenging free radicals. There has been growing evidence over the past three decades showing that malnutrition (e.g., dietary deficiencies of protein, selenium, and zinc) or excess of certain nutrients (e.g., iron and vitamin C) gives rise to the oxidation of biomolecules and cell injury. A large body of the literature supports the notion that dietary antioxidants are useful radioprotectors and play an important role in preventing many human diseases (e.g., cancer, atherosclerosis, stroke, rheumatoid arthritis, neurodegeneration, and diabetes). The knowledge of enzymatic and non-enzymatic oxidative defense mechanisms will serve as a guiding principle for establishing the most effective nutrition support to ensure the biological safety of manned space missions.
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PMID:Free radicals, antioxidants, and nutrition. 1236 82

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

A positive family history of coronary heart disease (CHD) is one of the most predictive risk factors of CHD. Many children with increased risk of CHD because of their positive family history of CHD do not present other risk factors, such as altered serum lipid profile. Oxidative stress plays an important part in the pathogenesis of atherosclerosis. Serum antioxidants and intracellular enzymatic antioxidants composed mainly of glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD) and glutathione reductase counterbalance oxidative stress. Diminished activity of this system may lead to accelerated progression of atherosclerosis. The aim of this study was to assess the activity of CAT, GSH-Px, SOD and glutathione reductase in children with a family history of premature CHD who did not present any other major risk factors of CHD (diabetes, obesity, dyslipidaemia or hypertension). Twenty-two healthy children from high-risk families, selected according to the National Cholesterol Education Program definition, were enrolled in the study. The control group comprised 18 children without a family history of CHD. All the children were healthy and had been screened for hyperlipidaemia, diabetes, hypertension and obesity prior to the study. The erythrocyte activity of CAT, GSH-Px, SOD and glutathione reductase was assessed. Children at high risk of CHD had a statistically significant lower level of GSH-Px and CAT activity than the children in the control group. There were no statistically significant differences in the activity of SOD and glutathione reductase.
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PMID:Activity of antioxidant enzymes in children from families at high risk of premature coronary heart disease. 1275 97

Physical activity (PA) is associated with a reduced risk of coronary heart disease, and may favorably modify the antioxidant-prooxidant balance. This study assessed the effects of aerobic PA training on antioxidant enzyme activity, oxidized LDL concentration, and LDL resistance to oxidation, as well as the effect of acute PA on antioxidant enzyme activity before and after the training period. Seventeen sedentary healthy young men and women were recruited for 16 weeks of training. The activity of superoxide dismutase in erythrocytes (E-SOD), glutathione peroxidase in whole blood (GSH-Px), and glutathione reductase in plasma (P-GR), and the oxidized LDL concentration and LDL composition, diameter, and resistance to oxidation were determined before and after training. Shortly before and after this training period they also performed a bout of aerobic PA for 30 min. The antioxidant enzyme activity was also determined at 0 min, 30 min, 60 min, 120 min, and 24 h after both bouts of PA. Training induces an increase in GSH-Px (27.7%), P-GR (17.6%), and LDL resistance to oxidation, and a decrease in oxidized LDL (-15.9%). After the bout of PA, an increase in E-SOD and GSH-Px was observed at 0 min, with a posterior decrease in enzyme activity until 30-60 min, and a tendency to recover the basal values at 120 min and 24 h. Training did not modify this global response pattern. Regular PA increases endogenous antioxidant activity and LDL resistance to oxidation, and decreases oxidized LDL concentration; 30 min of aerobic PA decreases P-GR and B-GSH-Px activity in the first 30-60 min with a posterior recovery.
Atherosclerosis 2003 Apr
PMID:Response of oxidative stress biomarkers to a 16-week aerobic physical activity program, and to acute physical activity, in healthy young men and women. 1281 16

Antioxidant component alterations in the aorta during atherogenesis were examined in atherosclerosis-susceptible (SUS) Japanese quail fed a cholesterol-supplemented (0.5% w/w) diet. Birds fed a non-supplemented diet provided information on the effects of aging on endogenous antioxidants. One hundred adult SUS males were used. Birds were sacrificed after 0, 4, 8 and 12 weeks on the diets and were examined for plaque development and corresponding antioxidant component alterations in aorta and myocardium. With aging, superoxide dismutase (SOD) activity was increased in both tissues, whereas aortic glutathione peroxidase (GPx) activity and myocardial glutathione reductase (GRd) activity decreased. Myocardial ascorbate levels increased with aging, with a reciprocal decrease in myocardial tocopherol levels. Following 4 weeks of cholesterol supplementation, aortic GRd decreased, SOD activity increased, but activities of GPx and catalase were unchanged. This same qualitative pattern of antioxidant enzyme changes was also found in myocardium. Thus, although aortic antioxidant enzyme changes produced by cholesterol feeding and aging showed some similarities, the early phase of atherogenesis does not simply reflect accelerated aging. In the late stages of atherogenesis, SOD activity returned to baseline, but other antioxidant enzymes remained unaltered from levels characterizing the early phase of lesion development. There was no detectable functional coupling between changes in GPx and GRd, nor between SOD (which produces hydrogen peroxide) and GPx or catalase (which utilize hydrogen peroxide as substrate). Previously reported alterations in erythrocyte antioxidant enzyme components during atherogenesis in quail were not predictive of changes in the corresponding enzymes in the aorta and myocardium.
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PMID:Alterations in aortic antioxidant components in an experimental model of atherosclerosis: a time-course study. 1457 93

We have investigated heme oxygenase (HO) and antioxidant status in the novel isolation and characterization of aortic endothelial cells (AECs) from a random bred wild-type strain (WILD) and selectively bred atherosclerosis-susceptible (SUS) and -resistant (RES) strains of Japanese quail. Cultured AECs expressed acetylated LDL, and were probed with endothelial and smooth muscle cell specific antibodies to confirm purity of culture. Subconfluent monolayers of RES AECs had higher HO activity than SUS AECs. At confluence, HO activity levels were similar among strains. However, RES AECs had higher HO-1 protein than WILD and SUS cells. Although ferritin protein levels were similar among the three strains, catalytic iron was higher in SUS AECs than WILD and RES cells. Glutathione levels were highest in SUS cells, intermediate in WILD, and lowest in RES, while glutathione reductase was higher in WILD and RES AECs than SUS AECs. We suggest that differences in atherosclerosis susceptibility between RES and SUS may be due, at least in part, to differences in endothelial HO and antioxidant components.
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PMID:Heme oxygenase and antioxidant status in cultured aortic endothelial cells isolated from atherosclerosis-susceptible and -resistant Japanese quail. 1457


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