dinoprost and Arteriosclerosis

Postaglandins(PG) and low-density lipoproteins (LDL) both are playing a key role in atherogenesis. Their interaction at the local vascular level is of central relevance in plaque formation and progression. Details of these complex actions however, still need to be elucidated. Lipoproteins are influencing the PG-production of arterial wall cells and platelets, while PGs in turn have been shown to regulate lipoprotein receptor binding and entry into the arterial wall. Modification of LDL severely influences arterial wall trapping and foam cell formation. During LDL-modification, isoprostanes, a new family of compounds generated by free radical catalysed action, independent of cyclooxygenase, are formed. 8-epi PGF(2alpha) the most well known member exerts a great variety of proatherogenic actions, among them vasoconstriction and platelet activation; it also serves as a mitogen and stimulator of endothelin release. The influence of various eicosanoids on lipoprotein modification, however, has not been assessed yet.

Topics: Arteriosclerosis; Dinoprost; Epoprostenol; Humans; Lipid Peroxidation; Lipoproteins, LDL; Prostaglandins E; Prostaglandins F

Long-term vascular complications still represent the main cause of morbidity and mortality in diabetic patients. Although randomized long-term clinical studies comparing the effects of conventional and intensive therapy have demonstrated a clear link between hyperglycemia and the development of complications of diabetes, they have not defined the mechanism through which excess glucose results in tissue damage. Evidence has accumulated indicating that oxidative stress may play a key role in the etiology of diabetic complications. Isoprostanes are emerging as a new class of biologically active products of arachidonic acid metabolism of potential relevance to human vascular disease. Their formation in vivo seems to reflect primarily, if not exclusively, a nonenzymatic process of lipid peroxidation. Enhanced urinary excretion of 8-iso-PGF(2alpha) has been described in association with both type 1 and type 2 diabetes mellitus, and correlates with impaired glycemic control. Besides providing a likely noninvasive index of lipid peroxidation in this setting, measurements of specific F(2) isoprostanes in urine may provide a sensitive biochemical end point for dose-finding studies of natural and synthetic inhibitors of lipid peroxidation. Although the biological effects of 8-iso-PGF(2alpha) in vitro suggest that it and other isoeicosanoids may modulate the functional consequences of lipid peroxidation in diabetes, evidence that this is likely in vivo remains inadequate at this time.

Topics: Animals; Antioxidants; Arachidonic Acids; Arteriosclerosis; Biomarkers; Coronary Disease; Diabetes Complications; Diabetes Mellitus; Dietary Supplements; Dinoprost; F2-Isoprostanes; Humans; Hyperglycemia; Lipid Peroxidation; Oxidative Stress; Protein Isoforms; Vitamin E

Lipid oxidation has been shown to be a prominent feature of atherosclerosis. The presence of isoprostanes and other lipid oxidation products has been clearly demonstrated in lesions. Furthermore, antibodies to oxidized phospholipids have been identified in animal and human models. Recent evidence suggests that oxidized phospholipids may activate all vascular cell types. The identification and isolation of particular oxidative products has provided some important information about the receptors for these active lipids.

Topics: Animals; Arteriosclerosis; Dinoprost; Humans; Isomerism; Oxidation-Reduction; Phospholipids

F2-isoprostanes are prostaglandin F2-like compounds being formed by non-enzymatic peroxidation of arachidonic acid in vivo. They have a variety of biological actions. The most important compound of this group is 8-epi-PGF(2 alpha) being capable to induce vasconstriction in particular of lung- and renal vascular tissue. Isoprostanes are present in esterified form; in free form they become available after hydrolysis by phospholipase A. An increase in isoprostanes is an important indicator of oxidative stress in-vivo due to a variety of different noxi such as metal- or non-metal ions for cigarette smoke. Isoprostanes show an activation of platelets; as a consequence of the interaction of 8-epi-PGF(2 alpha) with specific receptors platelet aggregation may be induced or may be enhanced together with other agonists. Due to these preliminary results isoprostanes could become an interesting substance in angiology in the future for diagnosis of oxidative stress as well as in the understanding of the pathogenesis of atherosclerosis.

Topics: Animals; Arteriosclerosis; Dinoprost; Humans; Lipid Peroxidation; Platelet Aggregation; Vasoconstriction

Isoprostanes are emerging as a new class of biologically active products of arachidonic acid metabolism of potential relevance to human vascular disease. Their formation in vivo seems to reflect primarily, if not exclusively, a nonenzymatic process of lipid peroxidation. Enhanced urinary excretion of 8-iso-PGF2 alpha has been described in association with cardiac reperfusion injury and with cardiovascular risk factors, including cigarette smoking, diabetes mellitus, and hypercholesterolemia. Besides providing a likely noninvasive index of lipid peroxidation in these settings, measurements of specific F2 isoprostanes in urine may provide a sensitive biochemical end point for dose-finding studies of natural and synthetic inhibitors of lipid peroxidation. Although the biological effects of 8-iso-PGF2 alpha in vitro suggest that it and other isoeicosanoids may modulate the functional consequences of lipid peroxidation, evidence that this is likely in vivo remains inadequate at this time.

Topics: Antioxidants; Arteriosclerosis; Biomarkers; Cardiovascular Diseases; Diabetes Mellitus; Dinoprost; F2-Isoprostanes; Free Radicals; Gas Chromatography-Mass Spectrometry; Humans; Hyperlipidemias; Immunoassay; Indicator Dilution Techniques; Lipid Peroxidation; Oxidative Stress; Platelet Aggregation; Prostaglandins F; Risk Factors; Thrombosis; Vasoconstrictor Agents

Cigarette smoking, a key risk factor for the development of vascular disease, is associated with an increased 8-epi-prostaglandin (PG) F(2alpha). Elevated 8-epi-PGF(2alpha) has been found in vascular tissue, blood and urine as well. We examined the influence of quitting cigarette smoking in 71 patients (38 males, 33 females; aged 32-67 a) with clinically manifested atherosclerosis and various risk factors. In addition, in eight patients with hypercholesterolemia without clinical manifestation of atherosclerosis quitting smoking was monitored as well. Twenty-six of the patients with manifested atherosclerosis and five with hypercholesterolemia restarted and the isoprostanes in plasma, serum and urine were monitored in these patients as well. Quitting cigarette smoking induces an immediate decline becoming significant after 1 or 2 weeks. Restarting smoking results in an increase in 8-epi-PGF(2alpha) reaching prevalues within almost 1 week. These findings indicate that the in vivo oxidation injury associated with cigarette smoking quickly decreases after quitting but increases soon after restarting immediately.

Topics: Adult; Aged; Arteriosclerosis; Biomarkers; Diabetes Complications; Diabetes Mellitus; Dinoprost; F2-Isoprostanes; Female; Humans; Hypercholesterolemia; Hypertension; Male; Middle Aged; Risk Factors; Smoking; Smoking Cessation; Time Factors

Familial hypercholesterolaemia (FH) may be associated with increased oxidative stress which may contribute to atherogenesis. Plasma lipid hydroperoxides (ROOHs), 8-epi PGF(2alpha) and alpha-tocopherol were measured in normal subjects and in newly referred heterozygous FH patients and used as indices of oxidative stress. ROOH levels were higher (+16%), albeit non-significantly, in FH patients than in controls subjects (4.4+/-0.3 vs. 3.8+/-0.3 micromol/l; n=51 and 40, respectively). 8-epi PGF(2alpha) levels were significantly greater (+56%) in the FH patients than in controls (0.43+/-0.06 vs. 0.27+/-0.05 nmol/l; P<0.05; n=14 and 16, respectively). FH patients with vascular disease had significantly higher (+32%) levels of ROOH compared with patients without vascular disease (4.9+/-0.40 vs. 3.7+/-0.33 micromol/l; P<0.05; n=27 and 24, respectively). Similarly, 8-epi PGF(2alpha) concentrations were higher (+100%) in the FH patients with vascular disease than in those without it (0.6+/-0.08 vs. 0.3+/-0.10 nmol/l; P<0.05; n=6 and 8, respectively). Absolute alpha-tocopherol levels in FH patients were similar to those in controls (21.0+/-0.70 vs. 23.8+/-1.30 micromol/l). When alpha-tocopherol levels were expressed relative to cholesterol, however, the concentrations were found to be significantly lower (-43%) in FH patients than in controls (2.9+/-0.10 vs. 5.1+/-0.40 micromol/mmol, P<0.0005). There were no differences in absolute or cholesterol standardised alpha-tocopherol levels in patients with and without vascular disease. These data suggest that oxidative stress is increased in FH-patients and is particularly pronounced in those patients with vascular disease. It is possible that increased oxidative stress may precede the development of vascular disease.

Topics: Adult; Arteriosclerosis; Biomarkers; Chromatography, High Pressure Liquid; Dinoprost; Female; Humans; Hyperlipoproteinemia Type II; Lipid Peroxides; Male; Middle Aged; Oxidative Stress; Probability; Reference Values; Risk Assessment; Sensitivity and Specificity; Vitamin E

The formation of prostacyclin (PGI(2)), thromboxane (TX) A(2), and isoprostanes is markedly enhanced in atherosclerosis. We examined the relative contribution of cyclooxygenase (COX)-1 and -2 to the generation of these eicosanoids in patients with atherosclerosis.. The study population consisted of 42 patients with atherosclerosis who were undergoing surgical revascularization. COX-2 mRNA was detected in areas of atherosclerosis but not in normal blood vessel walls, and there was evidence of COX-1 induction. The use of immunohistochemical studies localized the COX-2 to proliferating vascular smooth muscle cells and macrophages. Twenty-four patients who did not previously receive aspirin were randomized to receive either no treatment or nimesulide at 24 hours before surgery and then for 3 days. Eighteen patients who were receiving aspirin were continued on a protocol of either aspirin alone or a combination of aspirin and nimesulide. Urinary levels of 11-dehydro-TXB(2) and 2,3-dinor-6-keto-PGF(1alpha), metabolites of TXA(2) and PGI(2), respectively, were elevated in patients with atherosclerosis compared with normal subjects (3211+/-533 versus 679+/-63 pg/mg creatinine, P<0.001; 594+/-156 versus 130+/-22 pg/mg creatinine, P<0.05, respectively), as was the level of the isoprostane 8-iso-PGF(2alpha). Nimesulide reduced 2, 3-dinor-6-keto-PGF(1alpha) excretion by 46+/-5% (378.3+/-103 to 167+/-37 pg/mg creatinine, P<0.01) preoperatively and blunted the increase after surgery. Nimesulide had no significant effect on 11-dehydro-TXB(2) before (2678+/-694 to 2110+/-282 pg/mg creatinine) or after surgery. The levels of both products were lower in patients who were taking aspirin, and no further reduction was seen with the addition of nimesulide. None of the treatments influenced urinary 8-iso-PGF(2alpha) excretion.. Both COX-1 and -2 are expressed and contribute to the increase in PGI(2) in patients with atherosclerosis, whereas TXA(2) is generated by COX-1.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Aged; Anti-Inflammatory Agents, Non-Steroidal; Arteriosclerosis; Aspirin; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprost; Epoprostenol; F2-Isoprostanes; Female; Humans; Isoenzymes; Macrophages; Male; Membrane Proteins; Microscopy, Fluorescence; Muscle, Smooth, Vascular; Prostaglandin-Endoperoxide Synthases; Sulfonamides; Thromboxane A2; Thromboxane B2

An elevated plasma total homocysteine level (tHcy) is considered an independent risk factor for atherosclerosis. The mechanisms by which hyperhomocysteinemia induces atherosclerosis are only partially understood, but promotion of LDL oxidation and endothelial injury have been suggested. The purpose of this study was to test the hypothesis that a high plasma tHcy is associated in men with increased in vivo lipid peroxidation, as measured by plasma F2-isoprostane concentrations. We investigated this association in a subset of the participants in the Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) study. Of 256 male participants, a subsample of 100 consecutive men was selected for F2-isoprostane assays. The mean tHcy was 11.0 micromol/L, and the mean F2-isoprostanes was 29.6 ng/L. The simple correlation coefficient for association between tHcy and F2-isoprostane was 0.40 (P<0.001). In a linear regression model, the variables with the strongest associations with F2-isoprostane were tHcy (standardized coefficient 0.33, P<0.001), serum triglycerides (0.21, P=0.042), carbohydrate-deficient transferrin (0.15, P=0.132), and plasma lipid-standardized alpha-tocopherol (-0.11, P=0.252) (R2=0.24, P<0. 001 for model). Plasma F2-isoprostane levels increased linearly across quintiles of tHcy (P<0.001). The unadjusted mean (95% confidence interval) F2-isoprostanes was 47.5% greater in the highest tHcy quintile (37.4, 31.1 to 43.6 ng/L) than in the lowest quintile (25.3, 21.3 to 29.3 ng/L). Adjustment for the strongest other determinants of F2-isoprostane reduced this difference to 28. 2% (P=0.010). Our present data suggest that elevated fasting plasma tHcy is associated with enhanced in vivo lipid peroxidation in men.

Topics: Arteriosclerosis; Ascorbic Acid; beta Carotene; Dinoprost; Double-Blind Method; Fasting; Humans; Hyperhomocysteinemia; Linear Models; Lipid Peroxidation; Male; Middle Aged; Risk Factors; Transferrin; Triglycerides; Vitamin E

Significant disturbances of immune regulation of prostaglandine metabolism were found in patients with hypertension and obesity. Use of antisclerotic diet with low sodium contents promoted positive changes of clinical symptoms of diseases, in particular normalizations of process of immune regulation of prostaglandine metabolism connected with formation of natural antibodies.

Topics: Adult; Aged; Antibodies; Arteriosclerosis; Biomarkers; Diet, Sodium-Restricted; Dinoprost; Dinoprostone; Female; Humans; Hypertension; Male; Middle Aged; Obesity; Treatment Outcome

Recent years have seen increased numbers of children with conditions that contribute strongly to atherosclerotic disease, such as passive smoking, obesity, and dyslipidemia. In the present study, we evaluated the utility of non-invasive urinary markers in preventing lifestyle-related diseases by comparing lipid metabolism-related parameters with oxidative stress markers in school children.. Subjects were 85 first-grade students. The variables examined included the smoking in subjects' household; exercise habits; height and weight; blood pressure; and plasma total cholesterol, high-density lipoprotein cholesterol, triglyceride, leptin, blood sugar, urinary cotinine, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 8-isoprostaglandin F2α (IsoP).. Of the subjects, 10.6% were obese (% overweight ≥ 20%), 3.5% had a high-risk arteriosclerosis index (AI; 3 ≤ AI < 5), and 29.4% were passive smokers. No significant differences were seen between boys and girls for any of the measurement parameters. Both urinary 8-OHdG (6.8-24.5 ng/mg creatinine) and IsoP (0.9-7.4 ng/mg creatinine) were detected in all subjects, and a significant positive correlation was seen between the two markers. On multiple regression analysis using AI as an objective variable and all non-invasive markers as explanatory variables, urinary IsoP correlated most strongly with AI (P ≤ 0.01).. Risk factors for atherosclerosis in adults, such as obesity and hypercholesterolemia, are associated with oxidative stress and inflammation. The present findings of the strongest correlation between urinary IsoP and AI suggest that urinary IsoP may serve as a non-invasive and effective early marker in predicting risk in children of developing lifestyle-related diseases.

Topics: Arteriosclerosis; Biomarkers; Child; Dinoprost; Dyslipidemias; Female; Humans; Incidence; Japan; Lipids; Male; Overweight; Oxidative Stress; Risk Assessment; Risk Factors; Schools

Alterations in the elastic behavior of arteries is an early sign of vascular damage in atherogenesis and may be promoted by oxidative stress (OxS). However, studies designed for simultaneous assessment of arterial elasticity and OxS status in patients with peripheral arterial disease (PAD) are absent. The purpose of this study was to assess large (C1) and small artery elasticity (C2) and indices of OxS in patients with PAD as well as to investigate possible relationships between these parameters.. Arterial elasticity was assessed noninvasively by pulse wave analysis (PWA) and biochemical measurements were taken from 38 patients with PAD and from 28 matched control subjects. The elasticity indices of the arteries were derived from PWA based on the modified Windkessel model and the OxS status was measured using urinary 8-iso-prostaglandin F2alpha (F2-IsoPs) and plasma baseline diene conjugates of low-density lipoproteins (LDL-BDC).. Patients with PAD showed significantly reduced C1 and C2 and increased values of F2-IsoPs and LDL-BDC. There was an inverse association between C1 and F2-IsoPs, as well as between C2 and F2-IsoPs (R=-.3, P=.04; R=-.49, P=.002, respectively) in the patient group, but not in the controls. After controlling for potential confounders in a multiple regression model, the associations between C2 and F2-IsoPs remained significant in the patient group (P<.001).. The possible link between arterial elasticity and F2-IsoPs in patients with PAD suggests that oxidative modifications may be involved in alterations of arterial elastic properties in atherosclerosis.

Topics: Aged; Arteries; Arteriosclerosis; Biomarkers; Blood Glucose; Blood Pressure; Case-Control Studies; Cholesterol, HDL; Cholesterol, LDL; Creatinine; Dinoprost; Elasticity; Heart Rate; Humans; Intermittent Claudication; Linear Models; Lower Extremity; Male; Middle Aged; Oxidative Stress; Peripheral Vascular Diseases; Severity of Illness Index; Triglycerides

Hypercholesterolemia (HC) and atherosclerosis can elicit oxidative stress, coronary endothelial dysfunction, and myocardial ischemia, which may induce growth-factor expression and lead to myocardial neovascularization. We tested the hypothesis that chronic antioxidant intervention in HC would attenuate neovascularization and preserve the expression of hypoxia-inducible factor (HIF)-1alpha and vascular endothelial growth factor (VEGF).. Three groups of pigs (n=6 each) were studied after 12 weeks of normal or 2% HC diet or HC+antioxidant supplementation (100 IU/kg vitamin E and 1 g vitamin C daily). Myocardial samples were scanned ex vivo with a novel 3D micro-CT scanner, and the spatial density and tortuosity of myocardial microvessels were determined in situ. VEGF mRNA, protein levels of VEGF and VEGF receptor-1, HIF-1alpha, nitrotyrosine, and superoxide dismutase (SOD) were determined in myocardial tissue. The HC and HC+antioxidant groups had similar increases in serum cholesterol levels. HC animals showed an increase in subendocardial spatial density of microvessels compared with normal (160.5+/-11.8 versus 95.3+/-8.2 vessels/cm2, P<0.05), which was normalized in HC+antioxidant (92.5+/-20.5 vessels/cm2, P<0.05 versus HC), as was arteriolar tortuosity. In addition, HC induced upregulation of VEGF, HIF-1alpha, and nitrotyrosine expression and decreased SOD expression and activity, all of which were preserved by antioxidant intervention.. Changes in myocardial microvascular architecture invoked by HC are accompanied by increases in HIF-1alpha and VEGF expression and attenuated by antioxidant intervention. This underscores a role of increased oxidative stress in modulating myocardial microvascular architecture in early atherogenesis.

Topics: Animals; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiotonic Agents; Coronary Circulation; Diet, Atherogenic; Dinoprost; Enzyme Induction; Female; Gene Expression Profiling; Gene Expression Regulation; Heart; Hypercholesterolemia; Hypoxia-Inducible Factor 1, alpha Subunit; Imaging, Three-Dimensional; Myocardial Ischemia; Neovascularization, Pathologic; Oxidative Stress; Superoxide Dismutase; Swine; Tomography, X-Ray Computed; Transcription Factors; Tyrosine; Vascular Endothelial Growth Factor A; Vitamin E

Topics: Arteriosclerosis; Carotid Artery Diseases; Coronary Artery Disease; Dinoprost; Humans; Lipid Peroxidation; Logistic Models; Lupus Erythematosus, Systemic; Oxidative Stress; Tumor Necrosis Factor-alpha

Apolipoprotein A-II (apoA-II), the second major high-density lipoprotein (HDL) apolipoprotein, has been linked to familial combined hyperlipidemia. Human apoA-II transgenic mice constitute an animal model for this proatherogenic disease. We studied the ability of human apoA-II transgenic mice HDL to protect against oxidative modification of apoB-containing lipoproteins. When challenged with an atherogenic diet, antigens related to low-density lipoprotein (LDL) oxidation were markedly increased in the aorta of 11.1 transgenic mice (high human apoA-II expressor). HDL from control mice and 11.1 transgenic mice were coincubated with autologous very LDL (VLDL) or LDL, or with human LDL under oxidative conditions. The degree of oxidative modification of apoB lipoproteins was then evaluated by measuring relative electrophoretic mobility, dichlorofluorescein fluorescence, 9- and 13-hydroxyoctadecadienoic acid content, and conjugated diene kinetics. In all these different approaches, and in contrast to control mice, HDL from 11.1 transgenic mice failed to protect LDL from oxidative modification. A decreased content of apoA-I, paraoxonase (PON1), and platelet-activated factor acetyl-hydrolase activities was found in HDL of 11.1 transgenic mice. Liver gene expression of these HDL-associated proteins did not differ from that of control mice. In contrast, incubation of isolated human apoA-II with control mouse plasma at 37 degrees C decreased PON1 activity and displaced the enzyme from HDL. Thus, overexpression of human apoA-II in mice impairs the ability of HDL to protect apoB-containing lipoproteins from oxidation. Further, the displacement of PON1 by apoA-II could explain in part why PON1 is mostly found in HDL particles with apoA-I and without apoA-II, as well as the poor antiatherogenic properties of apoA-II-rich HDL.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Animals; Aorta; Aortic Diseases; Apolipoprotein A-I; Apolipoprotein A-II; Arteriosclerosis; Aryldialkylphosphatase; Cholesterol, HDL; Diet, Atherogenic; Dinoprost; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Hyperlipoproteinemia Type II; Lipoproteins, HDL; Lipoproteins, LDL; Lipoproteins, VLDL; Liver; Male; Mice; Mice, Transgenic; Oxidation-Reduction; Recombinant Fusion Proteins; Thiobarbituric Acid Reactive Substances

Mice lacking leukocyte type 12/15-lipoxygenase (12/15-LO) show reduced atherosclerosis in several models. 12/15-LO is expressed in a variety of cells, including vascular cells, adipocytes, macrophages, and cardiomyocytes. The purpose of this study was to determine which cellular source of 12/15-LO is important for atherosclerosis.. Bone marrow from 12/15-LO-/-/apoE-/- mice was transplanted into apoE-/- mice and vice versa. Deficiency of 12/15-LO in bone marrow cells protected apoE-/- mice fed a Western diet from atherosclerosis to the same extent as complete absence of 12/15-LO, although plasma 8,12-iso-iPF2alpha-IV, a measure of lipid peroxidation, remained elevated. 12/15-LO-/-/apoE-/- mice regained the severity of atherosclerotic lesion typical of apoE-/- mice after replacement of their bone marrow cells with bone marrow from apoE-/- mice. Peritoneal macrophages obtained from wild-type but not 12/15-LO-/- mice caused endothelial activation in the presence of native LDL. Absence of 12/15-LO decreased the ability of macrophages to form foam cells when exposed to LDL.. We conclude that macrophage 12/15-LO plays a dominant role in the development of atherosclerosis by promoting endothelial inflammation and foam cell formation.

Topics: Animals; Apolipoproteins E; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Arteriosclerosis; Autocrine Communication; Bone Marrow Transplantation; Cell Adhesion; Cell Differentiation; Cells, Cultured; Dinoprost; Endothelial Cells; Endothelium, Vascular; Foam Cells; Hyperlipoproteinemia Type II; Interleukin-4; Lipoproteins, LDL; Macrophages, Peritoneal; Mice; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Radiation Chimera; RNA, Messenger; Triglycerides

Circulating 8-iso-prostaglandin F 2alpha (8-iso-PGF 2alpha ) has been proposed as new indicator of oxidative stress, which is involved in the pathophysiologic changes of atherosclerosis. We proposed to test the hypothesis that 8-iso-PGF 2alpha is an independent predictor of symptomatic peripheral arterial disease (PAD).. A case-control study in 100 patients with symptomatic PAD and 100 control subjects matched for age, sex, and diabetes mellitus was conducted. Smokers and subjects using lipid-lowering drugs were excluded. Serum total 8-iso-PGF 2alpha was quantified with an enzyme immunoassay.. Median 8-iso-PGF 2alpha was higher in patients with PAD than in control subjects (63 vs 42 pg/mL; P = .001). Logistic regression with hypertension, body mass index, and creatinine, low-density lipoprotein (LDL) cholesterol, triglyceride, high-sensitivity C-reactive protein (hs-CRP), 8-iso-PGF 2alpha , and total homocysteine concentrations as independent variables and case-control status as dependent variable revealed significant odds ratios (OR) for hypertension (OR, 3.74; 95% confidence interval [CI], 1.85-7.53), low-density lipoprotein cholesterol (OR, 1.16, for an increment of 10 mg/dL; 95% CI, 1.07-1.27), high-sensitivity C-reactive protein (OR, 1.02, for an increment of 1 mg/L; 95% CI, 1.00-1.03), and 8-iso-PGF 2alpha (OR, 1.11, for an increment of 10 pg/mL; 95% CI, 1.03-1.20).. Serum total 8-iso-PGF 2alpha was an independent predictor of PAD in the population studied. This finding supports the hypothesis that 8-iso-PGF 2alpha is a risk marker for PAD. Our results indicate increased systemic oxidative stress in patients with PAD.

Topics: Aged; Aged, 80 and over; Arteriosclerosis; Biomarkers; Case-Control Studies; Dinoprost; Female; Humans; Male; Middle Aged; Oxidative Stress; Peripheral Vascular Diseases; Predictive Value of Tests

A growing body of evidence from animal studies supports the hypothesis that oxidative stress-mediated mechanisms play a central role in early atherogenesis. In contrast, clinical trials with antioxidant vitamins have not produced consistent results in humans with established atherosclerosis.. Low-density lipoprotein receptor-deficient mice (LDLR KO) were fed a high-fat diet for 3 months to induce atheroma. At this time, 1 group of mice was euthanized for examination of atherosclerosis, and 2 other groups were randomized to receive high-fat diet either alone or supplemented with vitamin E for 3 additional months. At the end of the study, LDLR KO on a vitamin E-supplemented fat diet had decreased 8,12-iso-isoprostane (iP)F(2alpha)-VI and monocyte chemoattractant protein-1 levels, but increased nitric oxide levels compared with mice on placebo. No difference in lipid levels was observed between the 2 groups. Compared with baseline, placebo group had progression of atherosclerosis. In contrast, vitamin E-treated animals showed a significant reduction in progression of atherosclerosis.. These results demonstrate that in LDLR KO, vitamin E supplementation reduces progression of established atherosclerosis by suppressing oxidative and inflammatory reactions and increasing nitric oxide levels.

Topics: Animals; Aorta; Arteriosclerosis; Biomarkers; Cholesterol; Dietary Fats; Dietary Supplements; Dinoprost; Disease Progression; Immunohistochemistry; Lipid Peroxidation; Mice; Mice, Knockout; Nitric Oxide; Receptors, LDL; Treatment Outcome; Triglycerides; Vitamin E

Diet and exercise can affect blood pressure and atherosclerotic risk.. The present study was designed to examine the effects of a short-term, rigorous diet and exercise intervention on blood pressure, hyperinsulinemia, and nitric oxide (NO) availability. Men (n=11) were placed on a low-fat, high-fiber diet combined with daily exercise for 45 to 60 minutes for 3 weeks. Pre- and post fasting blood was drawn for serum lipid, insulin, 8-isoprostaglandin F(2alpha) (8-iso-PGF(2alpha)), and glucose measurements. Anthropometric parameters, blood pressure (BP), and 24-hour urinary NO metabolite excretion (NO(X)), a marker of NO bioavailability, were measured. Systolic (P<0.01) and diastolic BP (P<0.01) and 8-iso-PGF(2alpha) decreased (P<0.05), whereas urinary NO(X) increased (P<0.05). There was a significant reduction in fasting insulin (P<0.01) and a significant correlation between the decrease in serum insulin and the increase in urinary NO(X) (r2=0.68, P<0.05). All fasting lipids decreased significantly, and the total cholesterol to high-density lipoprotein cholesterol ratio improved. Although body weight and body mass index (P<0.01) decreased, obesity was still present and there were no correlations between the change in body mass index and the change in insulin, BP, or urinary NO(X).. This intervention resulted in dramatic improvements in BP, oxidative stress, NO availability, and the metabolic profile within 3 weeks, mitigating the risk for atherosclerosis progression and its clinical sequelae.

Topics: Adult; Aged; Arteriosclerosis; Blood Pressure; Body Mass Index; Body Weight; Combined Modality Therapy; Dinoprost; Exercise; F2-Isoprostanes; Humans; Hypertension; Insulin; Male; Middle Aged; Nitric Oxide; Oxidative Stress

Diabetes mellitus (DM) is a well-established risk factor of cardiovascular diseases. We investigated the mechanism of the progression of arteriosclerosis in DM, focusing on the role of oxidative stress and insulin resistance in vivo. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an experimental model of type 2 DM, were assigned to 3 groups, based on supplementation with vitamin E (VE) or troglitazone (TR), a VE-derived agent which improves insulin-resistance. At 36 weeks, plasma and aortic tissue 8-iso-PGF2alpha contents, a vascular proliferating eicosanoid produced in vivo by oxidative stress, were measured by EIA. TGF-beta1 and TGF-beta1 receptor II were immunohistochemically analyzed. Histopathologically, medial area and the nuclear number of smooth muscle cells of the aorta were measured. The tissue 8-iso-PGF2alpha content (pg/g tissue) was significantly decreased by either VE or TR in the aorta (untreated-OLETF, 15,332+/-3,254 vs. TR-treated-OLETF, 7,092+/-1,992 or VE-treated-OLETF, 5,394+/-836, both p<0.01), but that in plasma decreased by only VE. VE and TR improved the increased the level of the actual medial area and the number of smooth muscle cells. The expression of TGF-beta1 was reduced, but TGF-beta1 receptor II was not. 8-iso-PGF2alpha may play an important role in the progression of arteriosclerosis. Antioxidant treatment may promise significant clinical benefits in the early diabetic stage.

Topics: Animals; Aorta; Arteriosclerosis; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dinoprost; Disease Progression; Eicosanoids; F2-Isoprostanes; Lipids; Male; Oxidative Stress; Rats; Rats, Inbred OLETF; Rats, Long-Evans; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta; Transforming Growth Factor beta1

The endothelial isoform of nitric oxide synthase (eNOS) has been considered to exert an antiatherosclerotic role through synthesis of NO. However, eNOS has been shown to generate superoxide, which could oxidize LDL and promote atherosclerosis. We sought to determine the role of eNOS in diet-induced fatty streak formation through the use of eNOS-deficient mice.. Mice were fed an atherogenic diet containing 15% fat, 1.25% cholesterol, and 0.5% sodium cholate for 12 weeks, and atherosclerotic lesions at the aortic root were measured after oil-red O staining. Unexpectedly, eNOS-deficient mice developed much smaller aortic lesions than did wild-type control mice (2544+/-1107 versus 7023+/-1569 microm2/section; P=0.03). This reduction in lesion formation could not be explained by changes in plasma levels of lipids and susceptibility of lipoproteins to oxidation. To examine whether eNOS contributed to the oxidation of LDL within the arterial wall, endothelial cells were isolated from the aorta of mice and incubated with native LDL in the absence or presence of N-Omega-nitro-L-arginine methyl ester (L-NAME), a specific NOS inhibitor. L-NAME significantly inhibited LDL oxidation by endothelial cells from wild-type animals (P<0.05), but it had no effect on LDL oxidation by endothelial cells from eNOS-deficient mice.. These data indicate that absence of eNOS-mediated LDL oxidation may contribute to the reduction of fatty-streak formation in eNOS-deficient mice.

Topics: Animals; Aortic Diseases; Arteriosclerosis; Cells, Cultured; Dinoprost; Endothelium, Vascular; Enzyme Inhibitors; F2-Isoprostanes; Female; Kinetics; Lipids; Lipoproteins, LDL; Mice; Mice, Inbred C57BL; Mice, Knockout; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III

Apolipoprotein E is a multifunctional protein synthesized by hepatocytes and macrophages. Plasma apoE is largely liver-derived and known to regulate lipoprotein metabolism. Macrophage-derived apoE has been shown to reduce the progression of atherosclerosis in mice. We tested the hypothesis that liver-derived apoE could directly induce regression of pre-existing advanced atherosclerotic lesions without reducing plasma cholesterol levels. Aged low density lipoprotein (LDL) receptor-deficient (LDLR(-/-)) mice were fed a western-type diet for 14 weeks to induce advanced atherosclerotic lesions. One group of mice was sacrificed for evaluation of atherosclerosis at base line, and two other groups were injected with a second generation adenoviruses encoding human apoE3 or a control empty virus. Hepatic apoE gene transfer increased plasma apoE levels by 4-fold at 1 week, and apoE levels remained at least 2-fold higher than controls at 6 weeks. There were no significant changes in plasma total cholesterol levels or lipoprotein composition induced by expression of apoE. The liver-derived human apoE gained access to and was retained in arterial wall. Compared with base-line mice, the control group demonstrated progression of atherosclerosis; in contrast, hepatic apoE expression induced highly significant regression of advanced atherosclerotic lesions. Regression of lesions was accompanied by the loss of macrophage-derived foam cells and a trend toward increase in extracellular matrix of lesions. As an index of in vivo oxidant stress, we quantitated the isoprostane iPF(2 alpha)-VI and found that expression of apoE markedly reduced urinary, LDL-associated, and arterial wall iPF(2 alpha)-VI levels. In summary, these results demonstrate that liver-derived apoE directly induced regression of advanced atherosclerosis and has anti-oxidant properties in vivo that may contribute to its anti-atherogenic effects.

Topics: Adenoviridae; Animals; Antioxidants; Aorta; Apolipoproteins E; Arteriosclerosis; Cholesterol; Diet, Atherogenic; Dinoprost; Disease Progression; Endothelium, Vascular; Extracellular Matrix; Gene Transfer Techniques; Humans; Liver; Mice; Mice, Knockout; Oxidative Stress; Receptors, LDL

Lipid peroxidation plays an important role in atherogenesis. Previous studies suggested that autoantibodies against epitopes of oxidized low-density lipoprotein may indicate the extent or rate of progression of atherosclerosis. The aim of this study was to investigate whether autoantibodies to oxidized phospholipids, such as oxidized cardiolipin (OxCL), correlate with levels of isoprostane F(2alpha)-VI, a sensitive marker of in vivo lipid peroxidation, as well as with the extent of atherosclerosis. Two groups of apolipoprotein E-deficient mice were fed chow with or without vitamin E (2000 IU/kg diet) for 16 weeks. In untreated animals, autoantibodies against OxCL and urinary, plasma, and aortic isoprostane F(2alpha)-VI levels increased significantly. Vitamin E treatment significantly reduced antibody titers, isoprostane levels, and atherosclerosis at the end of the study, compared with untreated mice. Autoantibodies to OxCL correlated with aortic isoprostane F(2alpha)-VI levels (r(2) = 0.42, P =.001 for IgG and r(2) = 0.63, P <.001 for IgM). Both aortic isoprostane F(2alpha)-VI levels (r(2) = 0.59, P <.001) and titers of OxCL antibodies (r(2) = 0.70, P <.001 for IgG and r(2) = 0.68, P <.001 for IgM) correlated with the extent of aortic atherosclerosis. The fact that the levels of autoantibodies to OxCL correlated with a sensitive direct measure of lipid peroxidation in vivo and that both autoantibodies and aortic isoprostane F(2alpha)-VI levels correlated with the extent of atherosclerosis suggests that antibodies to OxCL are a sensitive indicator of in vivo lipid peroxidation and atherosclerosis.

Topics: Analysis of Variance; Animals; Aorta; Apolipoproteins E; Arteriosclerosis; Autoantibodies; Biomarkers; Cardiolipins; Dinoprost; Immunoglobulin G; Immunoglobulin M; Lipid Peroxidation; Mice; Mice, Knockout; Vitamin E

PGI(2)and 8-epi-prostaglandin(PG)F(2 alpha)are antagonizing compounds. For both a key role in vascular pathology has been hypothesized. The isoprostane 8-epi-PGF(2 alpha)and the stable derivative of PGI(2), 6-oxo-PGF(1 alpha)were determined immunologically in the arterial wall of various species including humans. Human arterial tissue contained the highest amounts of 8-epi-PGF(2 alpha)and synthesized the lowest PGI(2). A significant negative correlation between 8-epi-PGF(2 alpha)and 6-oxo-PGF(1 alpha)was observed. Atherosclerotic segments showed significantly higher 8-epi-PGF(2 alpha)and lower 6-oxo-PGF(1 alpha). 8-epi-PGF(2 alpha)in the intima was higher than in the media, the highest amounts being found in foam-cell rich areas. Synthetic (activated) smooth muscle cells were associated with an enhanced 8-epi-PGF(2 alpha)as well as 6-oxo-PGF(1 alpha). Tissue samples derived from smokers contained more 8-epi-PGF(2 alpha)and produced less PGI(2). The by far highest 8-epi-PGF(2 alpha)/6-oxo-PGF(1 alpha)ratio was found in foam cell rich areas. Similar findings were obtained in rabbit and in minipig arteries. The total 8-epi-PGF(2 alpha)/6-oxo-PGF(1 alpha)ratio is low in normal tissue, increases significantly in an active atherosclerotic process and seems to be even further increased in an inactive atherosclerotic process. These findings are providing an information on the extent of oxidation injury at various sites of different types of atherosclerotic process.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Aged; Aged, 80 and over; Animals; Arteries; Arteriosclerosis; Dinoprost; F2-Isoprostanes; Female; Foam Cells; Humans; Male; Middle Aged; Oxygen; Phenotype; Rabbits; Radioimmunoassay; Smoking

The enzyme 12/15-lipoxygenase (12/15-LO) has been implicated in the oxidative modification of LDL. In a murine model, we tested the hypothesis that deletion of 12/15-LO decreases atherogenesis by reducing oxidant stress, as measured by 2 indices of lipid peroxidation: isoprostane generation and autoantibody formation to malondialdehyde (MDA)-LDL, an epitope of LDL formed as a result of oxidative modification.. 12/15-LO-deficient (12/15-LO(-/-)) mice were crossed with apolipoprotein E-deficient (apoE(-/-)) mice. At 10 weeks of age, atherosclerotic lesion initiation was significantly delayed in the double-knockout mice. The rate of lesion progression was diminished at 8 and 12 months, and even at 15 months, lesion size was reduced 50% (P<0.0005) compared with control apoE(-/-) mice. The urinary and plasma levels of the specific isoprostane 8,12-iso-iPF(2alpha)-VI, as well as IgG autoantibodies against MDA-LDL, were significantly reduced in the double-deficient mice in parallel with decreased atherosclerosis at all time points from 10 weeks to 15 months of age compared with apoE(-/-) controls.. Enzymatic action of 12/15-LO contributes significantly to atherosclerotic lesion initiation and propagation in this murine model. Strong positive correlations exist between lesion size, isoprostane levels, and MDA-LDL autoantibodies, providing in vivo evidence for an enzymatic (12/15-LO) component to lipid peroxidation and atherogenesis.

Topics: Animals; Aorta; Apolipoproteins E; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Arachidonic Acid; Arteriosclerosis; Autoantibodies; Cholesterol; Cholesterol, HDL; Dinoprost; Disease Models, Animal; Disease Progression; Immunohistochemistry; Lipid Peroxidation; Lipoproteins, LDL; Malondialdehyde; Mice; Mice, Inbred C57BL; Mice, Knockout

Nonhuman primates used in these studies had been fed for 5 years diets enriched with cholesterol and one of three classes of fatty acids: saturated, monounsaturated, or polyunsaturated fatty acids. Atherosclerotic iliac artery lipid extracts were quantitatively analyzed for cholesterol, cholesteryl esters, fatty acid composition, and a marker of lipid oxidation, the F(2)-isoprostanes. There was no significant difference in the mean accumulation of F(2)-isoprostanes among the different diet groups. To account for the small, individual variation in the arachidonate concentration the F(2)-isoprostane mass from each sample was normalized by dividing by arachidonate mass: F(2)-isoprostane mass/(mass arachidonate). At lower levels of cholesterol accumulation, the F(2)-isoprostane mass/(mass arachidonate) ratio was greater in lipids from POLY arteries compared to SAT arteries, but the reverse was true at high levels of cholesterol. F(2)-isoprostane/(mass arachidonate) increased with mole fraction linoleate for the SAT group, but decreased for the POLY group. In summary, these studies demonstrated that there is no simple explanation of how F(2)-isoprostane accumulation did not depend on the concentration of oxidizable lipids that promote free-radical lipid oxidation.

Topics: Animals; Arachidonic Acids; Arteriosclerosis; Chlorocebus aethiops; Cholesterol; Cholesterol Esters; Cholesterol, LDL; Diet, Atherogenic; Dietary Fats; Dinoprost; Fatty Acids; Free Radicals; Iliac Artery; Linoleic Acid; Lipid Peroxidation; Lipids; Oleic Acid; Oxidation-Reduction; Palm Oil; Plant Oils; Safflower Oil

Dietary polyunsaturated fats and vitamin E are associated with reduced risk for atherosclerosis, but in smokers, they could promote lipid oxidation. Therefore, we examined the effects of a high polyunsaturated fat diet and vitamin E supplementation on measures of lipid oxidation in cigarette smokers. Ten subjects who smoked >1 pack of cigarettes per day were sequentially fed the following: a baseline diet in which the major fat source was olive oil, a diet in which the major fat source was high-linoleic safflower oil, and finally, the safflower oil diet plus 800 IU vitamin E per day. LDL oxidation lag time and rate and plasma total F(2)-isoprostanes and prostaglandin F(2alpha) (PGF(2alpha)) were determined after 3 weeks on each diet. The safflower oil diet increased total F(2)-isoprostanes from 53.0+/-7.2 to 116.2+/-11.2 nmol/L and PGF(2alpha) from 3.5+/-0.2 to 5.5+/-0.5 nmol/L, without changing LDL oxidation parameters. Addition of vitamin E prolonged mean LDL oxidation lag time but, paradoxically, further increased F(2)-isoprostanes to 188.2+/-10.9 nmol/L and PGF(2alpha) to 7.8+/-0.4 nmol/L. These data suggest that vitamin E may function as a pro-oxidant in cigarette smokers consuming a high polyunsaturated fat diet.

Topics: Arteriosclerosis; Diet; Dietary Supplements; Dinoprost; F2-Isoprostanes; Fatty Acids, Unsaturated; Humans; Kinetics; Lipid Peroxidation; Lipoproteins, LDL; Oxidative Stress; Smoking; Vitamin E

Isoprostanes are known as reliable markers of in vivo oxidation injury. Cigarette smoking has been shown to be associated with a significant increase in 8-epi-PGF(2alpha), a major member of this family of compounds. Quitting smoking reduces 8-epi-PGF(2alpha) values to normal within a couple of weeks only. In this follow-up we checked the 8-epi-PGF(2alpha), values in plasma, serum and urine in 28 people who restarted smoking after a quitting attempt of various duration. 8-epi-PGF(2alpha)shows a certain increase after restarting smoking reaching a maximum after already 1 week. Continuation of smoking does not significantly further increase 8-epi-PGF(2alpha). These data indicate a fast response of restarting as on quitting smoking on in vivo oxidation injury. The oxidation injury reflected by 8-epi-PGF(2alpha)may be a key pathogenetic mechanism in smoking-induced vascular injury.

Topics: Adult; Aged; Arteriosclerosis; Biomarkers; Dinoprost; F2-Isoprostanes; Female; Humans; Hypercholesterolemia; Hypertension; Male; Middle Aged; Oxidative Stress; Smoking; Smoking Cessation; Time Factors

Lipoprotein peroxidation in the arterial wall has been implicated in atherogenesis. The superoxide radical is formed in arteries and can induce such oxidation. Extracellular superoxide dismutase (EC-SOD) occurs in high concentration in the vascular wall interstitium, and in this study, we examined the importance of the enzyme in atherogenesis. On an apolipoprotein E-null background, the limited aortic lesions induced by a 1-month atherogenic diet were larger in EC-SOD wild-type mice than in EC-SOD-null mice, whereas there were no differences between the EC-SOD genotypes in the larger lesions seen after 3 months on the diet or after 8 months on normal chow. Despite smaller or equal lesions in the EC-SOD-null mice, their cholesterol levels were somewhat higher. Also, on a wild-type background, there were no effects produced by the absence or presence of EC-SOD on atherogenic diet-induced aortic root lesions. The urinary excretion of the lipid peroxidation biomarker 8-isoprostaglandin F(2alpha) was related to the rates of atherogenesis in the mice but was not influenced by the EC-SOD genotype. Likewise, the EC-SOD status had no effect on the staining for oxidized low density lipoprotein epitopes in aortic root sections. Our findings suggest that EC-SOD has little influence on atherogenesis in mice.

Topics: Animals; Aorta; Apolipoproteins E; Arteriosclerosis; Cholesterol; Diet, Atherogenic; Dinoprost; F2-Isoprostanes; Female; Lipoproteins, LDL; Male; Mice; Mice, Knockout; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances

Lipid peroxidation and platelet activation are thought to be important contributors to the pathogenesis of atherosclerosis. The relevance of their interaction in vivo, however, is unknown.. LDL receptor-deficient (LDLR(-/-)) mice on a high-fat diet developed extensive atherosclerosis and had increased urinary levels of 8,12-iso-isoprostane (iP) F(2alpha)-VI and 2,3-dinor-thromboxane (Tx) B(2), markers of in vivo lipid peroxidation and platelet activation, respectively. Vitamin E supplementation suppressed 8,12-iso-iPF(2alpha)-VI biosynthesis and reduced atherosclerosis (65%) without having a significant effect on lipid levels or TxB(2) biosynthesis. Addition of the platelet inhibitor indomethacin to vitamin E simultaneously suppressed 8,12-iso-iPF(2alpha)-VI and TxB(2), significantly reduced soluble intercellular adhesion molecule-1 and monocyte chemoattractant protein-1, and remarkably, further reduced atherosclerosis (80%).. These results indicate that in vivo lipid peroxidation and platelet activation coexist in murine atherosclerosis and that lipid peroxidation does not contribute to platelet activation and reflects the oxidant component of the inflammatory response. Our findings suggest that oxidant stress and platelet activation represent 2 distinct therapeutic targets in atherogenesis. We propose that a combination of antioxidants and platelet inhibitors might be rationally evaluated in the prevention of progression of human atherosclerosis.

Topics: Animals; Antioxidants; Aorta; Arteriosclerosis; Cyclooxygenase Inhibitors; Diet, Atherogenic; Dietary Supplements; Dinoprost; Disease Models, Animal; Disease Progression; Female; Immunohistochemistry; Indomethacin; Lipid Peroxidation; Lipids; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Platelet Activation; Receptors, LDL; Thromboxane A2; Thromboxane B2; Vitamin E

Hyperlipidemia may increase endothelial damage and promote accelerated atherogenesis in graft coronary vasculopathy. To study the effects of hypercholesterolemia on coronary endothelial dysfunction, intimal hyperplasia, and lipid content, a porcine model of heterotopic heart transplantation, allowing nonacute rejection without immunosuppressive drugs, was used. A high cholesterol diet was fed to donor and recipient swine 1 month before and after transplantation. The endothelial function of coronary arteries of native and transplanted hearts from cholesterol-fed animals was studied in organ chambers 30 days after implantation and compared with endothelial function in arteries from animals fed a normal diet. The total serum cholesterol increased 3-fold in donors and recipients. Endothelium-dependent relaxations to serotonin, to the alpha(2)-adrenergic agonist UK14,304, and to the direct G-protein activator sodium fluoride were decreased significantly in allografted hearts compared with native hearts from both groups. Relaxations to the calcium ionophore A23187 and bradykinin were decreased significantly in allografts from animals fed the high cholesterol diet. The prevalence of intimal hyperplasia was significantly increased in coronary arteries from hypercholesterolemic swine. There was a significant increase in the lipid content of allograft arteries of hypercholesterolemic recipients. Hypercholesterolemia causes a general coronary endothelial dysfunction, increases the prevalence of intimal hyperplasia, and augments the incorporation of lipids in the vascular wall after heart transplantation. Hyperlipidemia accelerates graft coronary atherosclerosis through its effects on the endothelium.

Topics: Adrenergic alpha-Agonists; Animals; Arteriosclerosis; Biological Transport; Brimonidine Tartrate; Calcimycin; Calcium; Cholesterol, HDL; Cholesterol, LDL; Coronary Vessels; Diet, Atherogenic; Dinoprost; Dose-Response Relationship, Drug; Endothelium, Vascular; Erythrocyte Count; Female; Free Radical Scavengers; Heart Transplantation; Hematocrit; Hemoglobins; Hypercholesterolemia; Hyperplasia; Ionophores; Male; Myocardium; Postoperative Period; Potassium Chloride; Quinoxalines; Serotonin; Swine; Transplantation, Homologous; Tunica Intima; Vasodilation

Measurement of the F(2)-isoprostane, 8-epi-PGF(2alpha) is increasingly used as a sensitive and reliable marker of lipid peroxidation in vivo. Because the majority of 8-epi-PGF(2alpha) in plasma is associated with lipoproteins, it is possible that 8-epi-PGF(2alpha) derived from polyunsaturated fatty acid-rich food may become incorporated within these lipoproteins during synthesis and could contribute to the levels detected in plasma. In this study, we evaluated the postprandial effect of a single fast-food meal (McDonald's Big Mac meal, McDonald's Corp., London, England) on plasma total 8-epi-PGF(2alpha) in nine healthy subjects. Blood was collected before and 2 h postprandially. 8-Epi-PGF(2alpha) was measured by immunoaffinity extraction and gas chromatography-mass spectrometry. Fasting plasma 8-epi-PGF(2alpha) (875 +/- 25 pM) increased postprandially (956 +/- 23 pM, p <.05), although no significant change was observed in the normalized concentrations (2. 78 +/- 0.1 vs. 2.95 +/- 0.3 nmol/mmol arachidonic acid). Plasma lipid hydroperoxides, fatty acids, vitamin E, total antioxidant status, cholesterol, and triglycerides were not altered. Plasma glucose increased postmeal (4.4 +/- 0.1 vs. 4.9 +/- 0.1 mM, p <.05). These results indicate that the overall contribution of this lipid-rich meal to plasma 8-epi-PGF(2alpha) and other lipid peroxidation markers was small.

Topics: Adult; Antioxidants; Arachidonic Acid; Arteriosclerosis; Biomarkers; Dietary Fats; Dinoprost; Eating; F2-Isoprostanes; Female; Humans; Lipid Peroxidation; Male; Middle Aged

This study investigates how strenuous arm exercise affects oxidized-low density lipoprotein (O(X)-LDL) mediated-platelet activation in patients with SCI. Ten patients with SCI and ten age- and sex-matched healthy subjects exercised strenuously using an arm crank ergometer. The following measurements were taken both when the subjects were at rest, and immediately after exercise: plasma lipid profile, O(X)-LDL mediated platelet aggregability and [Ca(2+)]i, urinary 11-dehydro-thromboxane B2 (11-dehydro-TXB2) and 8-iso-prostaglandin F(2alpha), (8-iso-PG F(2alpha)) contents, and plasma NO metabolite (nitrite plus nitrate) level. Based on these measurements, the major findings of this study can be summarized as follows: 1) the SCI group had higher urinary 8-iso-PGF(2alpha) and 11-dehydro-TXB2 contents, but a lower plasma nitrite plus nitrate level than the control group; 2) at rest, the SCI group had a higher platelet aggregability and [Ca(2+)]i, and O(X)-LDL-potentiated platelet activation than the control group; 3) O(X)-LDL-potentiated platelet aggregation was enhanced by strenuous arm exercise in both groups, but the effect of exercise was more pronounced in the SCI group than in the control group; 4) treating the platelet with L-arginine inhibited O(X)-LDL-potentiated platelet activation in both groups. The study concludes that individuals with SCI had more extensive resting and exercise-enhanced O(X)-LDL-potentiated platelet activation and greater amounts of preformed lipid peroxides than those without SCI. Therefore, supplementation therapy with antioxidants may be needed for patients with SCI, especially in a strenuous arm exercise period.

Topics: Adult; Arm; Arteriosclerosis; Calcium; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Dinoprost; Exercise Test; F2-Isoprostanes; Female; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Nitrates; Nitric Oxide; Nitrites; Oxidative Stress; Platelet Activation; Platelet Aggregation; Platelet Count; Risk Factors; Spinal Cord Injuries; Thromboxane B2

Isoprostanes (IP) have been identified as reliable markers of in vivo oxidation injury. Recently, in vascular tissue and blood as well as urine of cigarette smokers, increased IP values have been discovered. We examined 47 adults (26 males, 21 females; aged 30-66 years), admitted to a cardiovascular unit on an outpatient basis, with various risk factors but without any sign of manifestation of atherosclerosis. Refraining from cigarette smoking for a few days resulted in a significant drop of plasma, serum, and urinary 8-epi-PGF(2alpha). Thereafter, a further continuous decrease was monitored, reaching a steady state after about 4 weeks after quitting cigarette smoking. Prevalues of 8-epi-PGF(2alpha) were higher, depending on the type and number of risk factors; the decrease after quitting, however, was comparable. These results indicate that exsmokers may rapidly recover from their enhanced in vivo oxidation.

Topics: Adult; Aged; Arteriosclerosis; Biomarkers; Dinoprost; F2-Isoprostanes; Female; Humans; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Oxidative Stress; Risk Factors; Smoking Cessation; Time Factors

Homocysteine is a risk factor for the development of atherosclerosis and its thrombotic complications. We have employed an animal model to explore the hypothesis that an increase in reactive oxygen species and a subsequent loss of nitric oxide bioactivity contribute to endothelial dysfunction in mild hyperhomocysteinemia. We examined endothelial function and in vivo oxidant burden in mice heterozygous for a deletion in the cystathionine beta-synthase (CBS) gene, by studying isolated, precontracted aortic rings and mesenteric arterioles in situ. CBS(-/+) mice demonstrated impaired acetylcholine-induced aortic relaxation and a paradoxical vasoconstriction of mesenteric microvessels in response to superfusion of methacholine and bradykinin. Cyclic GMP accumulation following acetylcholine treatment was also impaired in isolated aortic segments from CBS(-/+) mice, but aortic relaxation and mesenteric arteriolar dilation in response to sodium nitroprusside were similar to wild-type. Plasma levels of 8-epi-PGF(2alpha) (8-IP) were somewhat increased in CBS(-/+) mice, but liver levels of 8-IP and phospholipid hydroperoxides, another marker of oxidative stress, were normal. Aortic tissue from CBS(-/+) mice also demonstrated greater superoxide production and greater immunostaining for 3-nitrotyrosine, particularly on the endothelial surface. Importantly, endothelial dysfunction appears early in CBS(-/+) mice in the absence of structural arterial abnormalities. Hence, mild hyperhomocysteinemia due to reduced CBS expression impairs endothelium-dependent vasodilation, likely due to impaired nitric oxide bioactivity, and increased oxidative stress apparently contributes to inactivating nitric oxide in chronic, mild hyperhomocysteinemia.

Topics: Acetylcholine; Animals; Aorta; Arteriosclerosis; Cystathionine beta-Synthase; Dinoprost; Disease Models, Animal; Endothelium, Vascular; F2-Isoprostanes; Heterozygote; Humans; Hyperhomocysteinemia; In Vitro Techniques; Lipid Peroxides; Mice; Mice, Mutant Strains; Nitroprusside; Reactive Oxygen Species; Risk Factors; Thrombosis; Tyrosine; Vasodilation

Isoprostanes (IP) are a new family of compounds formed during oxidation injury. 8-epi-prostaglandin (PG) F2alpha, a vasoconstrictory and mitogenic substance, is increased in hyperlipidemia in blood and urine as well as at the vascular level in the intima, in particular along foam cells. Similarly, cigarette smoking is associated with an immediate increase in 8-epi-PGF2alpha and a quick drop after quitting. Also diabetes and even the more a combination of risk factors (for the development of atherosclerosis) results in increased 8-epi-PGF2alpha in various compartments. Others, such as sex, age, hypertension and obesity were of minor influence. These findings further indicate, that in-vivo oxidation injury as reflected by increased IP may play a relevant role in atherogenesis. IP may serve as useful markers to assess oxidation injury at a local level.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Anticholesteremic Agents; Arteriosclerosis; Blood Component Removal; Blood Vessels; Child; Child, Preschool; Dinoprost; Female; Humans; Hyperlipidemias; Immunohistochemistry; Lipoproteins, LDL; Male; Middle Aged; Molecular Structure; Smoking; Thiobarbituric Acid Reactive Substances; Vasoconstrictor Agents

Evidence for increased oxidant stress has been reported in human atherosclerosis. However, no information is available about the importance of in situ oxidant stress in relation to plaque stability. This information is relevant because the morbidity and mortality of atherosclerosis are essentially the consequences of acute ischemic syndromes due to unstable plaques. We studied 30 carotid atherosclerotic plaques retrieved by endarterectomy from 18 asymptomatic (stable plaques) and 12 symptomatic patients (unstable plaques). Four normal arteries served as controls. After lipid extraction and ester hydrolysis, quantitation of different indices of oxidant stress were analyzed, including hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatetraenoic acids (EETs), ketoeicosatetraenoic acids (oxo-ETEs), and F2-isoprostanes using online reverse-phase high-performance liquid chromatography tandem mass spectrometry (LC/MS/MS). All measurements were carried out in a strictly double-blind procedure. We found elevated levels of the different compounds in atherosclerotic plaques. Levels of HETEs were 24 times higher than EETs, oxo-ETEs, or F2-isoprostanes. Levels of HETEs, but not those of EETs, oxo-ETEs or F2-isoprostanes, were significantly elevated in plaques retrieved from symptomatic patients compared with those retrieved from asymptomatic patients (1, 738 +/- 274 vs. 1,002 +/- 107 pmol/ micromol lipid phosphorous, respectively; P < 0.01). One monooxygenated arachidonate species, 9-HETE, which cannot be derived from known enzymatic reactions, was the most abundant and significant compound observed in plaques, suggesting that nonenzymatic lipid peroxidation predominates in advanced atherosclerosis and may promote plaque instability.

Topics: Arteriosclerosis; Chromatography, High Pressure Liquid; Dinoprost; Humans; Hydroxyeicosatetraenoic Acids; Lipid Peroxidation; Oxidative Stress

This study's aim was to determine whether biochemical risk factors such as lipoprotein(a), fibrinogen, homocysteine, and insulin, as well as low-density lipoprotein (LDL) particle size, were predictive of carotid intimamedia thickness (IMT), an early marker of atherosclerosis, in subjects with familial hypercholesterolemia (FH). We also determined whether plasma 8-isoprostane, as a marker of in vivo lipid oxidation, correlated with carotid IMT. Twenty-two homozygous and 20 heterozygous subjects with FH were compared with 20 normocholesterolemic controls. On univariate analysis, plasma total and LDL cholesterol, the cholesterol-years score (CYS), lipoprotein(a), and fibrinogen, but not homocysteine or insulin, were positively related, and high-density lipoprotein (HDL) cholesterol was negatively related to carotid IMT. However, on multivariate analysis, only LDL cholesterol and the CYS predicted carotid IMT (multiple r = 0.82; r2 = 0.68; p <0.0001). The subjects with FH had large rather than small dense LDL particles, and plasma 8-isoprostane levels were not increased. LDL cholesterol and the CYS, or "cholesterol bulk" are the pivotal determinants of atherosclerosis and are the strongest predictors of carotid IMT in FH.

Topics: Adult; Arteriosclerosis; Carotid Stenosis; Cholesterol, LDL; Dinoprost; F2-Isoprostanes; Female; Heterozygote; Homozygote; Humans; Hyperlipoproteinemia Type II; Lipoprotein(a); Male; Risk Factors

Isoprostanes are a new family of compounds generated by the free radical catalyzed action on arachidonic acid. Formed during oxidation they have been claimed to be a reliable indicator of in vivo oxidation injury. We assessed the amount of 8-epi-PGF2alpha in human surgical specimens as compared to PGI2 (via its stable metabolite 6-oxo-PGF1alpha), the major compound generated by vascular tissue. 8-epi-PGF2alpha is low in normal vascular tissue as is the 8-epi-PGF2alpha/6-oxo-PGF1alpha ratio. The vessels of smokers in general exhibited an increased 8-epi-PGF2alpha (r=0.82) and a decreased 6-oxo-PGF1alpha (r=0.71). The 8-epi-PGF2alpha/6-oxo-PGF1alpha ratio is, not significantly, increased in vessels derived from hyperlipidemics and hypertensives. These findings indicate that lipid peroxidation occurs within the human arterial wall as evidenced by 8-epi-PGF2alpha, probably further decreasing the synthesis of PGI2 and promoting atherogenic mechanisms.

Topics: 6-Ketoprostaglandin F1 alpha; Age Factors; Aged; Arteriosclerosis; Blood Vessels; Dinoprost; Epoprostenol; F2-Isoprostanes; Female; Humans; Immunoassay; In Vitro Techniques; Male; Middle Aged

Apolipoprotein E (apoE) is the major apolipoprotein of the CNS. Differential expression of apoE isoforms has been linked to longevity and to the pathogenesis of Alzheimer's disease. Several studies have demonstrated that this glycoprotein is important in mature as well as in aging CNS, where it may serve neurotrophic and/or neuroprotective functions. Some reports have shown that apoE-deficient mice have age-dependent neurodegeneration and cognitive impairment; others have not confirmed these observations. ApoE-deficient mice also develop hypercholesterolemia on a chow diet and have in vivo increased plasma lipid peroxidation products. F2-isoprostanes are prostaglandin F2alpha isomers and chemically stable peroxidation products of arachidonic acid. Both isoprostane F2alpha-III and isoprostane F2alpha-VI were markedly elevated in the brains of aged apoE-deficient mice compared with either wild-type C57 Bl/6 mice or a distinct mouse model of hypercholesterolemia, the low-density lipoprotein receptor-deficient mouse. By contrast, no difference in isoprostane levels was observed in young apoE-deficient mice compared with age-matched wild-type control mice. Our findings indicate that disorder of lipid metabolism in the absence of apoE can induce an age-dependent increase in brain lipid peroxidation products.

Topics: Aging; Animals; Apolipoproteins E; Arteriosclerosis; Biomarkers; Cerebellum; Cerebral Cortex; Dinoprost; Disease Models, Animal; Hypercholesterolemia; Lipid Peroxidation; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, LDL

Oxidative modification of low density lipoprotein (LDL) has been implicated in atherogenesis. Evidence consistent with this hypothesis includes the presence of oxidized lipids in atherosclerotic lesions, the newly discovered biological properties conferred on LDL by oxidation and the acceleration of atherogenesis by in vivo delivery of the gene for 15-lipoxygenase, an oxidizing enzyme present in atherosclerotic lesions. However, it is still unknown whether oxidative stress actually coincides with the evolution of the disease or whether it is of functional relevance to atherogenesis in vivo. Isoprostanes are products of arachidonic acid catalyzed by free radicals, which reflect oxidative stress and lipid peroxidation in vivo. Elevation of tissue and urinary isoprostanes is characteristic of human atherosclerosis. Here, deficiency in apolipoprotein E in the mouse (apoE-/-) resulted in atherogenesis and an increase in iPF2alpha-VI, an F2-isoprostane, in urine, plasma and vascular tissue. Supplementation with vitamin E significantly reduced isoprostane generation, but had no effect on plasma cholesterol levels in apoE-/- mice. Aortic lesion areas and iPF2alpha-VI levels in the arterial wall were also reduced significantly by vitamin E. Our results indicate that oxidative stress is increased in the apoE-/- mouse, is of functional importance in the evolution of atherosclerosis and can be suppressed by oral administration of vitamin E.

Topics: Animals; Aorta; Apolipoproteins E; Arteriosclerosis; Cholesterol; Dinoprost; Isomerism; Mice; Mice, Mutant Strains; Oxidative Stress; Vitamin E

Accumulation of monocyte-derived foam cells in the arterial intima is a major event in the development of atherogenesis. We have examined whether native and oxidized lipoprotein(a) (Lp(a)) can induce adhesion of monocytic cells to aortic endothelium. The extensive oxidation of paired samples of Lp(a) and low-density lipoprotein (LDL) was achieved by O2.-/OH. free radicals produced by gamma radiolysis of water, leading to similar values for the formation of peroxidation markers (conjugated dienes, TBARS, 8-epi-PGF2alpha) for both Lp(a) and LDL. Rabbit aortic segments were incubated for 5 h in the presence of equimolar concentrations of native and oxidized preparations of Lp(a) and LDL (125 micromol cholesterol/l, corresponding to 40 and 30 mg protein/l for Lp(a) and LDL, respectively). The aortic segments were incubated with rhodamin-isothiocyanate labeled U937 monocytic cells for 30 min and cell adhesion was quantified by fluorescent microscopy. Native Lp(a), and to a larger extent oxidized Lp(a), significantly increased U937 cell adhesion by 2.3 and 2.7 fold compared to controls (P < 0.005 and P < 0.001, respectively). Monocytic cell adhesion was also increased by native LDL (1.6 fold, P < 0.005), and to a greater extent by oxidized LDL (2.3 fold, P < 0.001). Thus native Lp(a) enhances the adhesive properties of the arterial endothelium which may account for its proatherogenic action. Furthermore, our results show that oxidized Lp(a), as well as oxidized LDL, are potent stimuli of monocyte adhesion to endothelial cells.

Topics: Animals; Aorta, Thoracic; Arteriosclerosis; Cell Adhesion; Dinoprost; Endothelium, Vascular; Free Radicals; Gamma Rays; Lipid Peroxidation; Lipoprotein(a); Lipoproteins, LDL; Male; Monocytes; Oxidation-Reduction; Rabbits; Thiobarbituric Acid Reactive Substances; Tumor Cells, Cultured

F2-Isoprostanes are prostaglandin (PG) isomers formed in situ in cell membranes by peroxidation of arachidonic acid. 8-epi PGF2alpha and IPF2alpha-I are F2-isoprostanes produced in humans which circulate in plasma and are excreted in urine. Measurement of F2-isoprostanes may offer a sensitive, specific, and noninvasive method for measuring oxidant stress in clinical settings where reactive oxygen species are putatively involved. We determined whether isoprostanes were present in human atherosclerotic lesions, where lipid peroxidation is thought to occur in vivo. 8-epi PGF2alpha ranged from 1.310-3.450 pmol/micromol phospholipid in atherectomy specimens compared with 0.045-0.115 pmol/micromol phospholipid (P < 0.001) in vascular tissue devoid of atherosclerosis. Corresponding values of IPF2alpha-I were 5.6-13.8 vs. 0.16-0.44 pmol/micromol phospholipid (P < 0.001). Levels of the two isoprostanes in vascular tissue were highly correlated (r = 0.80, P < 0.0001). Immunohistochemical studies confirmed that foam cells adjacent to the lipid necrotic core of the plaque were markedly positive for 8-epi PGF2alpha. These cells were also reactive with anti-CD68, an epitope specific for human monocyte/macrophages. 8-epi PGF2alpha immunoreactivity was also detected in cells positive for anti-alpha-smooth muscle actin antibody, which specifically recognizes vascular smooth muscle cells. Our results indicate that 8-epi PGF2alpha and IPF2alpha-I, two distinct F2-isoprostanes and markers of oxidative stress in vivo, are present in human atherosclerotic plaque. Quantitation of these chemically stable products of lipid peroxidation in target tissues, as well as in biological fluids, may aid in the rational development of antioxidant drugs in humans.

Topics: Adult; Aged; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Aorta; Arteries; Arteriosclerosis; Carotid Arteries; Dinoprost; Foam Cells; Humans; Isomerism; Lipid Peroxidation; Male; Middle Aged; Oxidative Stress; Phospholipids; Pulmonary Artery

Oxidative modification of LDL is believed to play a major role in atherogenesis. As major lipid peroxidation products oxygenated linoleic acid derivatives and oxysterols have been described in human atherosclerotic lesions. Here we report that human lesions contain isoprostanes as peroxidation products of arachidonic acid at a level of 27.1 +/- 21.2 pg/mg wet weight (n = 10), which corresponds to 75.9 +/- 59.3 pg/mg dry weight, n contrast, human umbilical veins (n = 10), which were used as nonatherosclerotic control vessels, contain much smaller amounts of isoprostanes (1.4 +/- 0.7 pg/mg wet weight, which corresponds to 11.7 +/- 6.2 pg/mg dry weight), and there are significant differences between the two types of vessels. As major products of linoleic acid oxidation, racemic hydroxy linoleate isomers were detected in the lesional ester lipids. In human lesions, the hydroxy linoleic acid/linoleic acid ratio was about 0.5%, a result indicating that 5 out of 1000 linoleate residues are present as hydroxylated derivatives. In umbilical veins, no hydroxy linoleic acid could be detected. These data show that human atherosclerotic lesions contain increased amounts of hydroxy linoleic acid isomers and isoprostanes when compared with nonatherosclerotic vessel wall and suggest a link between local lipid peroxidation and progression of atherosclerosis. For evaluation of the degree of lipid peroxidation, the determination of the hydroxy linoleic acid/linoleic acid ratio appears to be more suitable than the isoprostane content.

Topics: Aged; Arachidonic Acid; Arteries; Arteriosclerosis; Chromatography, High Pressure Liquid; Dinoprost; Female; Humans; Linoleic Acid; Linoleic Acids; Linoleic Acids, Conjugated; Lipid Peroxidation; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Umbilical Veins

This study tested the hypothesis that functional abnormalities of carotid and ocular arteries may improve after short-term regression of atherosclerosis, before regression of structural abnormalities.. We examined effects of short-term dietary treatment of atherosclerosis on carotid and ocular vascular responses to serotonin and to platelet activation by collagen in vivo. Three groups of monkeys were studied: normal cynomolgus monkeys, monkeys fed an atherogenic diet for 34 months, and atherosclerotic monkeys that were fed a regression diet for 8.6 +/- 1.1 months (mean +/- SE). We measured changes in carotid blood flow (using a Doppler probe), retinal blood flow (using microspheres), and diameter of the internal carotid artery (using quantitative angiography). Endothelium-dependent relaxation to acetylcholine was studied in rings of internal carotid artery in vitro.. Carotid blood flow increased in response to both serotonin and collagen in normal monkeys, decreased in response to both agents in atherosclerotic monkeys, and was restored toward normal after regression. Serotonin had little effect on retinal blood flow in normal monkeys and produced a marked decrease in retinal blood flow in atherosclerotic monkeys; the vasoconstrictor response to serotonin was reduced after regression. Activation of platelets by collagen increased blood flow in normal monkeys, decreased blood flow in atherosclerotic monkeys, and had little effect after regression. Alterations in responses of the internal carotid artery were consistent with changes in carotid and ocular blood flow. Endothelium-dependent relaxation in vitro was impaired by atherosclerosis and was restored toward normal by regression. There was no reduction in intimal area of the atherosclerotic lesion in common carotid and ophthalmic arteries from regression monkeys, despite a marked reduction in cholesteryl ester.. Within a few months of regression of atherosclerosis, endothelial function and hyperresponsiveness of carotid and ocular arteries to serotonin and platelet activation return toward normal. Functional improvement is associated with resorption of lipid from atherosclerotic lesions, but with little reduction in size of intimal lesions.

Topics: Acetylcholine; Animals; Arteriosclerosis; Carotid Artery, Internal; Cholesterol; Diet, Atherogenic; Dinoprost; In Vitro Techniques; Macaca fascicularis; Male; Muscle Contraction; Muscle Relaxation; Nitroprusside; Reference Values; Regional Blood Flow; Retinal Artery; Serotonin

The lipoxygenase product 15-hydroxyeicosatetraenoic acid (15-HETE) was shown to be the most important eicosanoid formed in the atherosclerotic rabbit aorta. The aim of the present study was to compare the effects of 15-HETE and its hydroperoxy precursor 15-HpETE with those of other vasoconstrictor and vasodilator agents in arteries from rabbits fed either a control or a cholesterol-rich diet for 16 and 30 weeks. 5-Hydroxytryptamine (5-HT) aggregated platelets and thrombin caused contractions of isolated rabbit aortas. The contractile responses elicited by platelets from control animals were similar to those evoked by platelets from atherosclerotic rabbits. After 16 weeks of hypercholesterolemia, the contractile responses were either augmented (5-HT), unchanged (platelets) or reduced (thrombin). After 30 weeks of hypercholesterolemia, the responses to all contractile agents used had decreased. In both aortas and pulmonary arteries the endothelium-dependent relaxations to the calcium ionophore, A23167, and to acetylcholine were progressively lost and the endothelium-independent relaxations to nitroglycerin were reduced by the progressing hypercholesterolemia. The 15-lipoxygenase metabolites contracted the isolated thoracic aorta and pulmonary artery from control rabbits and to a lesser extent those of the cholesterol-fed rabbits. After raising the tone in these vessels with prostaglandin F2 alpha PGF2 alpha) or noradrenaline, 15-HpETE induced relaxations which were not significantly influenced by the development of fatty streaks. Our data illustrate that the contractions of the blood vessel wall to 15-HETE, like those to other vasoconstrictors, are markedly reduced by developing atherosclerosis. In contrast, the relaxations to 15-HpETE in the rabbit arteries remain unaltered after 16 to 30 weeks of hypercholesterolemia. This is unlike the reactions to other vasodilators, which are markedly reduced.

Topics: Acetylcholine; Animals; Arachidonate 15-Lipoxygenase; Arteriosclerosis; Calcimycin; Dinoprost; Hydroxyeicosatetraenoic Acids; Hypercholesterolemia; In Vitro Techniques; Leukotrienes; Lipid Peroxides; Male; Muscle, Smooth, Vascular; Nitroglycerin; Platelet Aggregation; Rabbits; Thrombin; Vasoconstrictor Agents; Vasodilator Agents

Endothelial dysfunction caused by the early atherosclerotic process or by endothelial exposure to atherogenic lipids, including lysophosphatidylcholine (lysoPC), is characterized by a selective impairment of responses mediated by the pertussis toxin-sensitive Gi-2 protein. Experiments were performed to analyze the mechanisms underlying this effect. Bradykinin (BK: Gi-2 protein-independent), serotonin (5-HT: Gi-2 protein-dependent), or direct activation of the G(i-2)-protein by mastoparan increased the release of endothelium-derived nitric oxide (EDNO) from porcine arterial endothelial cells (EC). LysoPC decreased the release of EDNO caused by 5-HT, but did not affect the response to BK or mastoparan. LysoPC did not increase production of superoxide radicals detected by lucigenin-enhanced chemiluminescence. Western blot analysis showed no difference in the level of immunoreactive Gi alpha-2 between control and lysoPC-treated cells. Activation of the Gi-2 protein by serotonergic or alpha 2-adrenoceptor stimulation decreased the pertussis toxin-catalyzed ADP-ribosylation of Gi alpha-2 protein in membranes from control but not lysoPC-treated cells. However, direct activation of the Gi-2 protein by mastoparan inhibited the ADP-ribosylation in membranes from control and lysoPC-treated cells. The toxin-catalyzed reaction was reduced in lysoPC-treated cells or lysoPC-treated membranes. LysoPC reduced the ability of endothelin to increase GTP gamma S binding to the Gi-2 protein but did not affect the activity of mastoparan. These results suggest that lysoPC inhibits a pertussis toxin-sensitive signaling pathway in EC by an effect consistent with receptor:Gi-2-protein uncoupling.

Topics: Animals; Arteriosclerosis; Blotting, Western; Bradykinin; Dinoprost; Endothelium, Vascular; GTP-Binding Protein alpha Subunits, Gi-Go; Lysophosphatidylcholines; Muscle, Smooth, Vascular; Nitric Oxide; Pertussis Toxin; Superoxides; Swine; Vasodilation; Virulence Factors, Bordetella

Oxidation of low-density lipoproteins (LDL) is well known to increase the atherogenic risk. Active smoking has been claimed to be associated with a significant oxidant stress determined by enhanced LDL oxidation and isoprostane formation. We assessed the susceptibility of LDL to oxidation in 9 healthy non-smokers and 7 smokers before and after three and five hours' exposure to passive smoking. Baseline values for the lag time, diene formation, malondialdehyde and isoprostanes differed in part significantly. In contrast to the data on active smoking, passive exposure to cigarette smoke did not significantly affect any of these parameters, nor diene formation and electrophoretic mobility in smokers and non-smokers alike. These results indicate that a single exposure to passive smoking does not induce relevant oxidation of LDL in men.

Topics: Adult; Arteriosclerosis; Dinoprost; F2-Isoprostanes; Female; Humans; Lipoproteins, LDL; Male; Malondialdehyde; Oxidation-Reduction; Risk Factors; Smoking; Tobacco Smoke Pollution

Topics: Arteriosclerosis; Cerebral Arteries; Dinoprost; Humans; In Vitro Techniques; Muscle Contraction; Nifedipine; Papaverine; Spasm; Time Factors

Topics: Aged; Angina Pectoris; Arteriosclerosis; Calcium Channel Blockers; Coronary Vasospasm; Coronary Vessels; Dinoprost; Female; Humans; In Vitro Techniques; Prostaglandins F; Serotonin; Vasoconstriction

The metabolism of [1-14C]arachidonic acid [( 1-14C]AA) by washed platelets from macaques and human subjects was investigated. The results were as follows: At substrate levels of 1 microM, similar amounts of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), prostaglandin D2 (PGD2), and thromboxane A2 (TXA2), measured as thromboxane B2 (TXB2), were produced from [1-14C]AA by platelets from rhesus, Celebes black, and cynomolgus macaques and humans. An increase in the AA concentration from 1 microM to 20 microM decreased the TXB2: PGD2 ratio (aggregator: antiaggregator) from greater than 5 to less than 2 in all series. In the human series, the ratio decrease was due to an increase in PGD2 production; in the macaque series, PGD2 production increased and TXB2 production decreased. Under basal conditions and at 1 microM AA concentrations, the amounts of prostaglandins and thromboxanes produced by platelets from male and female rhesus macaques were the same. An increase in substrate concentration from 1 microM to 20 microM AA decreased TXB2 production and increased PGD2 production to the same extent in platelets from male and female rhesus macaques. Imidazole increased prostaglandin production and decreased TXB2 production by platelets from both male and female rhesus macaques. The TXB2: PGD2 ratios were reduced below 1.5; there was no difference between the ratios in the two series. In the presence of 1 mM imidazole, greater amounts of prostaglandins and thromboxanes were produced in the male than in the female series. These data indicate that macaque's platelets are a suitable model for the study of AA metabolism in human platelets.

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Arteriosclerosis; Blood Platelets; Chromatography, Thin Layer; Dinoprost; Dinoprostone; Female; Humans; Macaca; Male; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Prostaglandins D; Prostaglandins E; Prostaglandins F; Sex Factors; Thromboxane B2

Effect of dexamethasone administration on aortic morphology, cholesterol content and synthesis of prostaglandins from (14C)-arachidonic acid in aorta of spontaneously atherosclerosis susceptible pigeons was examined. Dexamethasone markedly inhibited the synthesis of prostaglandin E2 and stimulated the synthesis of prostaglandin I2 in aorta. In aorta of glucocortocoid treated animals, endothelial abnormalities noted in control birds were decreased and numerous surface protrusions or 'microvilli' were noted. The possibility that glucocorticoid induced inhibition of PGE2 synthesis in pigeon aorta may contribute to improved aortic morphology is discussed.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Aorta; Arachidonic Acid; Arachidonic Acids; Arteriosclerosis; Cholesterol; Columbidae; Dexamethasone; Dinoprost; Dinoprostone; Endothelium; Epoprostenol; Male; Microscopy, Electron, Scanning; Microvilli; Prostaglandins; Prostaglandins E; Prostaglandins F

We have briefly summarized only the data obtained in our own laboratory without including an extensive literature review. We have evaluated the changes in platelet membrane phospholipids and prostanoid formation in platelets. In atherosclerosis platelets show an activated prostanoid formation, whereas the plasma PGI2 levels are decreased.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Arachidonic Acid; Arachidonic Acids; Arteriosclerosis; Blood Platelets; Coronary Disease; Dinoprost; Humans; Middle Aged; Prostaglandins; Prostaglandins E; Prostaglandins F; Reference Values; Serum Albumin, Bovine

Topics: Animals; Arteriosclerosis; Blood Platelets; Cholesterol, Dietary; Coronary Vessels; Dinoprost; Electrocardiography; Heart Rate; Male; Microsomes; Prostaglandins F; Rabbits; Thromboxane A2; Thromboxane B2; Thromboxanes

In our ongoing studies of the interrelationship between platelets and the vascular wall we found that an accurate estimate could be made of the clinical condition and more effective therapy prescribed when we monitored alterations in the plasma levels of TXB2. For this purpose we devised a radioimmunoassay with I125-TXB2-Tyramide. Patients with ischemic heart disorders, cerebral apoplexy, diabetes mellitus, Buerger's disease, Takayasu disease etc., all had statistically high levels of TXB2 as compared with healthy controls. In particular, patients with myocardial infarction, cerebral thrombosis and/or hemorrhage all revealed increases in levels of TXB2 and these levels increased in parallel with a worsening of the clinical condition, and there was always a re-increase in TXB2 level before a recurrence of an attack. As plasma TXB2 levels clearly reflect thrombogenic disorders, the assessment of these levels on a routine basis, enables a more accurate diagnosis, an indication of possible recurrences, and more effective chemotherapy and rehabilitation.

Topics: Adolescent; Adult; Arteriosclerosis; Arteriosclerosis Obliterans; Child; Chromatography, Gel; Circadian Rhythm; Coronary Disease; Diabetes Mellitus; Dinoprost; Female; Humans; Intracranial Embolism and Thrombosis; Male; Middle Aged; Prostaglandins F; Takayasu Arteritis; Thromboangiitis Obliterans; Thromboxane B2; Thromboxanes