Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In members of the families whose parents had atherosclerosis complicated by macrofocal myocardial infarction or stroke, the serum level of lipid peroxidation products was correlated to enzymatic activity of neutrophil and red blood cells oxidation-antioxidation. In persons with hereditary predisposition to atherosclerosis both with clinical signs of atherosclerosis and phenotypically healthy against the control group there was elevated content of plasma acylhydroperoxides and hypoactivity of neutrophil myeloperoxidase. Determination of lipid peroxidation products by malonic dealdehyde showed this parameter to be higher in members of the families of the study group and in those with cardiovascular disorders. For those whose parents had atherosclerosis versus control subjects there were no differences in the activity of superoxide dismutase, glutation peroxidase and catalase in the blood red cells. Shifts in lipid peroxidation and activity of blood myeloperoxidase are identical in type and may represent a pathogenetic ling in formation of hereditary predisposition to cardiovascular disorders of atherosclerotic origin, the detection of which becomes feasible in a subclinical period.
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PMID:[Indicators of lipid peroxidation in the blood in hereditary predisposition to arteriosclerosis]. 233 43

Myocardial ischaemia results from complex interrelated processes involving progression of atherosclerosis, thrombosis, coronary spasm, platelet aggregation and local release of products from the arachidonic acid cascade. Endothelium-dependent responsiveness contributes to the local regulation of coronary blood flow, and the presence of endothelial damage may result in enhanced contraction of the smooth muscle. Drugs which have been used for the treatment of angina pectoris are able to reduce myocardial oxygen consumption. This concept will further be developed in the near future with beta-blocking agents with vasodilating properties, potent long acting nitrates (nicorandil), bradycardic agents (AQA 39 or AS-AH 208), and new calcium antagonists. However, future prospects in the treatment of angina pectoris include: drugs modifying the arachidonic acid cascade by increasing synthesis or release of prostacyclin (nafazatrom) or decreasing prostacyclin degradation (almitrine), or blocking thromboxane A2 synthetase (dazoxiben) or thromboxane A2 receptors (BM 13177) or, blocking the lipoxygenase pathway (nafazatrom) or prostacyclin analogues (iloprost); more clot-specific thrombolytic agents and new oral anticoagulant drugs; free-radical scavengers such as superoxide dismutase, catalase or peroxidase and drugs inhibiting xanthine-oxidase; anti-platelet drugs such as ticlopidine which blocks the fibrinogen receptors of platelets; drugs preventing the progression of atherosclerosis lesions such as nifedipine or verapamil in animals fed high-lipid diets; drugs which could modify myocardial metabolism during ischaemia. In this context, trimetazidine acts through prevention of ischaemia-induced decrease in ATP cellular storages, inhibition of potassium leak, decrease in free-radical production and thromboxane A2 synthesis and increase in prostacyclin synthesis. These new concepts provide an important contribution to the understanding of the pathophysiology of myocardial ischaemia. This explains the considerable development of pharmacological research for new agents in the treatment of angina pectoris.
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PMID:[Treatment of angina pectoris. New perspectives]. 294 45

Oxidative damage to the vascular endothelium may play an important role in the pathogenesis of atherosclerosis and aging, and may account in part for reduced vascular prostacyclin (PGI2) synthesis associated with both conditions. Using H2O2 to induce injury, we investigated the effects of oxidative damage on PGI2 synthesis in cultured endothelial cells (EC). Preincubation of EC with H2O2 produced a dose-dependent inhibition (inhibitory concentration [IC50] = 35 microM) of PGI2 formation from arachidonate. The maximum dose-related effect occurred within 1 min after exposure although appreciable H2O2 remained after 30 min (30% of original). In addition, H2O2 produced both a time- and dose-dependent injury leading to cell disruption, lactate dehydrogenase release, and 51Cr release from prelabeled cells. However, in dramatic contrast to H2O2 effects on PGI2 synthesis, loss of cellular integrity required doses in excess of 0.5 mM and incubation times in excess of 1 h. The superoxide-generating system, xanthine plus xanthine oxidase, produced a similar inhibition of PGI2 formation. Such inhibition was dependent on the generation of H2O2 but not superoxide in that catalase was completely protective whereas superoxide dismutase was not. H2O2 (50 microM) also effectively inhibited basal and ionophore A23187 (0.5 microM)-stimulated PGI2 formation. However, H2O2 had no effect on phospholipase A2 activity, because ionophore A23187-induced arachidonate release was unimpaired. To determine the effects on cyclooxygenase and PGI2 synthase, prostaglandin products from cells prelabeled with [3H]arachidonate and stimulated with ionophore A23187, or products formed from exogenous arachidonate were examined. Inhibition of cyclooxygenase but not PGI2 synthase was observed. Incubation of H2O2-treated cells with prostaglandin cyclic endoperoxide indicated no inhibition of PGI2 synthase. Thus, in EC low doses of H2O2 potently inhibit cyclooxygenase after brief exposure whereas larger doses and prolonged exposure are required for classical cytolytic effects. Surprisingly, PGI2 synthase, which is known to be extremely sensitive to a variety of lipid peroxides, is not inhibited by H2O2. Lipid solubility, enzyme location within the EC membrane, or the local availability of reducing factors may explain these results, and may be important determinants of the response of EC to oxidative stress.
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PMID:Effect of hydrogen peroxide on prostaglandin production and cellular integrity in cultured porcine aortic endothelial cells. 299 39

Studies of the catalase and apolipoprotein A-I genes are pertinent to the understanding of human disease. Not only are these genes involved in acatalasemia and atherosclerosis, respectively, but they are also important gene markers for chromosome 11, deletions of which are involved in the development of Wilms tumor. We have used in situ hybridization to localize these genes to specific bands on chromosome 11. Hybridization with a catalase cDNA yielded a significant number of cells (38%) exhibiting label at band 11p13. A high percentage of metaphase cells (50%) hybridized with a human genomic fragment containing the gene for apolipoprotein A-I displayed labeling at 11q13.
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PMID:Localization of the human catalase and apolipoprotein A-I genes to chromosome 11. 310 17

We have examined whether the toxic effects of homocysteine on cultured endothelial cells could result from the formation and action of hydrogen peroxide. In initial experiments with a cell-free system, micromolar amounts of copper were found to catalyze an oxygen-dependent oxidation of homocysteine. The molar ratio of homocysteine oxidized to oxygen consumed was approximately 4.0, which suggests that oxygen was reduced to water. The addition of catalase, however, decreased oxygen consumption by nearly one-half, which suggests that H2O2 was formed during the reaction. Confirming this hypothesis, H2O2 formation was detected using the horseradish peroxidase-dependent oxidation of fluorescent scopoletin. Ceruloplasmin was also found to catalyze oxidation of homocysteine and generation of H2O2 in molar amounts equivalent to copper sulfate. Finally, homocysteine oxidation was catalyzed by normal human serum in a concentration-dependent manner. Using cultured human and bovine endothelial cells, we found that homocysteine plus copper could lyse the cells in a dose-dependent manner, an effect that was completely prevented by catalase. Homocystine plus copper was not toxic to the cells. Specific injury to endothelial cells was seen only after 4 h of incubation with homocysteine plus copper. Confirming the biochemical studies, ceruloplasmin was also found to be equivalent to Cu++ in its ability to cause injury to endothelial cells in the presence of homocysteine. Since elevated levels of homocysteine have been implicated in premature development of atherosclerosis, these findings may be relevant to the mechanism of some types of chronic vascular injury.
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PMID:Endothelial cell injury due to copper-catalyzed hydrogen peroxide generation from homocysteine. 351 79

Homogenates of control and diet-induced atherosclerotic aortas of rabbit were prepared and the levels of DNA, protein, free and esterified cholesterol, and six enzymes known to be associated with various subcellular organelles [N-acetyl-beta-glucosaminidase, beta-galactosidase (lysosomes); cytochrome oxidase (mitochondria); neutral alpha-glucosidase (endoplasmic reticulum); 5'-nucleotidase (plasma membrane); catalase (peroxisomes)] were compared between control and atherosclerotic preparations. The levels of prostaglandins I2, E2, and F2 alpha, based on DNA, also were measured by radioimmunoassay. Atherosclerotic aortas were significantly enriched in catalase activity (440%) and in each of the acid hydrolases (395 and 630%), based on DNA, as well as in free (630%) and esterified cholesterol (930%), based on tissue wet weight, compared to control aortas. The control level of prostaglandin I2 was 10-fold higher than that of prostaglandin E2, which was 3-fold higher than that of prostaglandin F 2 alpha. Prostaglandin I2 doubled in amount with advanced atherosclerosis, while prostaglandin E2 increased over 10-fold, resulting in twice the amount of prostaglandin I2 than E2 in advanced atherosclerosis; the level of prostaglandin F2 alpha did not appear to change significantly with atherosclerosis. Increased levels of prostaglandins I2 and E2 were correlated significantly with increased aortic total cholesterol content (based on DNA) but not increased serum cholesterol levels. N-Acetyl-beta-glucosaminidase activity also was correlated significantly to aortic total cholesterol content and beta-galactosidase activity, as well as to the level of prostaglandin I2; in contrast, N-acetyl-beta-glucosaminidase was not significantly correlated to prostaglandin E2. The association of prostaglandins I2 and E2 with aortic total cholesterol suggests the participation of prostaglandins in the response of arterial cells to lipid accumulation in atherosclerosis. The specific association of aortic prostaglandin I2 level and N-acetyl-beta-glucosaminidase activity further suggests a possible role for this prostaglandin during arterial intralysosomal cholesterol accumulation.
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PMID:Arterial prostaglandins and lysosomal function during atherogenesis. I. Homogenates of diet-induced atherosclerotic aortas of rabbit. 389 3

This report validates and expands further the interpretation of our findings on prostaglandins and lysosomes in rabbit aortic homogenates (see paper I of this series) to enzymatically isolated and separated aortic cell populations during atherogenesis. Evidence is provided by which isolated arterial cells may be considered representative of in situ increases of diseased aortic tissue prostaglandin I2 and E2 levels, as well as lysosomal acid hydrolase activities and total cholesterol content based on DNA. Increasing latency of aortic lysosomal N-acetyl-beta-glucosaminidase activity was confirmed and correlated with increasing severity of atherosclerosis, in parallel to increasing levels of prostaglandin I2 but not increasing levels of prostaglandin E2. Ultrastructural observations also confirmed aortic intracellular lipid accumulation within lysosomes and as lipid droplets. Consistent with these relationships, separated low density, lipid-filled aortic cells were especially increased in total (197%) and latent (15%) lysosomal acid hydrolase activities, catalase activity (274%), total cholesterol (151%), and in both prostaglandin I2 (67%) and E2 (325%) levels based on DNA, as compared to control aortic cells or more normal-appearing high-density diseased aortic smooth muscle cells; high-density diseased aortic cells were increased in prostaglandin E2 but similar in latent acid hydrolase activity compared to control aortic cells. Since the total cholesterol content of rabbit atherosclerotic aortas was evidenced more intracellularly (75%) than extracellularly (25%) in this study, the association of increased prostaglandin I2 and E2 levels with low-density lipid-filled cells suggest the participation of these prostaglandins in the genesis of aortic foam cells during arterial lipid accumulation in rabbit atherosclerosis. The association of increasing prostaglandin I2 levels and increasing latent lysosomal N-acetyl-beta-glucosaminidase activities also implicates a possible relationship between this prostaglandin and lysosomal membranes of aortic cells, either primary or secondary to intralysosomal lipid accumulation.
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PMID:Arterial prostaglandins and lysosomal function during atherogenesis. II. Isolated cells of diet-induced atherosclerotic aortas of rabbit. 392 57

Hepatocatalase peroxidase, an active peroxidase-oxidase subunit isolated from beef-liver catalase, prevents cholesterol deposition and aortic atherosclerosis in cholesterol-fed rabbits and has no apparent toxicity or undesirable de effects. No allergic or immunological reactions have been observed. The participation of this enzymatic subunit in homeostatic control mechanisms and its potential pharmacological value in the control of human atherosclerosis are suggested.
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PMID:Prevention of induced atherosclerosis by peroxidase. 601 53

A series of biochemical and morphological studies has focused on the properties and origins of lipid laden foam cells in experimentally induced atherosclerosis in rabbits. Lipids inclusions present in these cells occupy half or more of the cytoplasmic volume and are of two kinds: cytoplasmic lipid droplets composed predominantly of cholesteryl esters and lysosomes in which substantial quantities of free cholesterol have accumulated. The foam cells exhibit some properties of macrophages but not others. They possess high levels of acid hydrolases and catalase and Fc membrane receptors can be detected on their surface. Only about one third of the foam cells, however, exhibit C3 receptors and few if any of the cells appear to contain or secrete lysozyme.
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PMID:Characterization of foam cells in experimental atherosclerosis. 693 40

The lipoproteins of human peripheral lymph and plasma were separated according to particle size by polyacrylamide gradient gel electrophoresis. All samples of lymph contained lipoproteins that moved to the same positions on the gel as plasma LDL and plasma HDL. Some samples of lymph also contained lipoproteins with the mobility of VLDL and IDL. The lymph lipoproteins corresponding to plasma LDL reacted with anti-LDL serum and those corresponding to plasma HDL reacted with anti-HDL serum. In the lipoprotein fraction with the mobility of HDL, the proportion of particles larger than catalase was greater in lymph than in plasma. It is suggested that the shift in size distribution towards larger HDL particles in lymph compared with plasma is due to uptake of cholesterol from extravascular tissue by HDL particles after they have reached the interstitial fluid from the plasma, rather than to preferential movement of larger particles across the capillary walls.
Atherosclerosis 1982 Jul
PMID:Further evidence for the role of high density lipoprotein in the removal of tissue cholesterol in vivo. 711 79


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