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

Cholesterol esterase activity was estimated in homogenates of rat arterial wall using radioactive cholesteryl oleate incorporated into phospholipid vesicles as a substrate. The labeled oleic acid was separated from the ester by addition of benzene-chloroform-methanol mixture. Under these conditions, two pH optima were found at about 4.5 and 7.5. Most of the activities at pH 4.5 and 7.5 were found in the lysosomal and microsomal fraction, respectively. No enzyme activity was detected when the substrate vesicles were prepared with phosphatidylethanolamine or sphingomyelin, but the activity was higher when the substrate vesicles were prepared with phosphatidylserine and highest when they were prepared with phosphatidylcholine. The relationship between enzyme regulation and lipid deposition in the arterial wall is discussed.
Atherosclerosis 1979 Jul
PMID:Studies of cholesterol esterase in rat arterial wall. 3 82

However great the success in the therapy of hypertension, atherosclerosis and ischemic heart disease has been gained today by recent efficient drugs, the definite healing of patients is not yet attained. The late discovery of reserpine, such an efficient drug of plant origin against hypertension, convinced so far reluctant scientists to consider the chemical compounds of the plant world. With respect to this traditional medical knowledge, it seems necessary to define more accurately the specificity of these healings-sometimes recommended unspecifically for a whole branch of medicine. This experimental verification should not use inconsiderately the present-day classification of diseases; there should be an awareness that conventional experimental methods in pharmacology are often unsuitable for revealing the real biological activity of one or another medicinal plant. The interest in the millennial empirical field of health care is acknowledged by the World Health Organization which promotes research and development of traditional medicine, along with investigations into its psychosocial and ethnographic aspects. These studies cover a number of plants growing in Bulgaria that have a healing effect in hypertension, atherosclerosis and ischemic heart disease according to the data of traditional medicine. Using screening methods, extracts and chemically pure substances were investigated; extraction was done with solvents such as water, ether, chloroform, dichloretan, ethanol, methanol, and acetone. Most of the experiments were carried out on anesthetized cats, rabbits and dogs. The substances tested were applied mainly intravenously, and in some experiments orally. Chronic experiments were also carried out on wakeful dogs with induced hypertension, on animals fed on an atherogenic diet, and on animals with induced arrhythmia and coronary spasm. Data are presented of clinical examination of some plants or of active substances isolated from them. Major results of these studies are presented for the following plants: Garlic, Geranium; Hellebore; Mistletoe; Olive; Valerian; Hawthorn; Pseucedanum arenarium; Periwinkle; Fumitory. For another 50 plants growing in Bulgaria and in other countries the author presents his and other investigators' experimental and clinical data about hypotensive, antiatheromatous and coronarodilatating action.
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PMID:Plants and hypotensive, antiatheromatous and coronarodilatating action. 57 53

Pharmacologic doses of dehydroepiandrosterone (DHEA), a steroid hormone produced naturally by the adrenal cortex, may lower plasma lipoprotein levels in humans and reduce the severity of experimental atherosclerosis in rabbits. Effects of DHEA on cells of the vascular wall, particularly endothelial cells (EC), which are in direct contact with the plasma, have not been documented. The authors have found that micromolar doses of DHEA induce a consistent and reversible morphologic change in cultured EC derived from the human umbilical vein. During 24 hours of exposure to DHEA, cultured EC became loaded with phase-dense, perinuclear cytoplasmic granules, which persisted while DHEA remained in the culture medium. Certain steroids related to DHEA, particularly 17-ketosteroids, also induced perinuclear cytoplasmic granules. The granules lost their phase-density after fixed monolayers were extracted using ethanol or methanol. The granules did not form in media made with lipoprotein-deficient serum, suggesting that serum lipoproteins were involved in formation of the granules. Ultrastructurally, the granules were identical to multilamellar lipid structures, a type of pleomorphic lipid-containing lysosome found in foam cells. The granules were identified as lysosomes by positive reaction for acid phosphatase. The mechanism by which DHEA induces formation of lysosomal lipid structures remains to be determined.
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PMID:Dehydroepiandrosterone and related steroids induce multilamellar lipid structures in cultured human endothelial cells. 214 Sep 27

Lipid peroxidation may play a significant role in the initiation and progression of atherosclerotic plaque. Freshly harvested normal and atherosclerotic human aortic tissue, coronary arteries and explanted vein grafts were snap frozen at -70 degrees C. Folch reagent (chloroform-methanol 2:1, v/v) was used to extract lipids from the homogenates. These extracts were assayed for cholesterol, phospholipid and triglyceride content. Lipid peroxide complexes in vessels were measured fluorometrically. Atherosclerotic plaque from patients with aortic aneurysmal and occlusive disease and coronary artery disease contained significantly greater amounts of cholesterol (15.54 +/- 9.71 vs 3.39 +/- 1.14 mg/g tissue) than controls (p less than 0.01). Lipid peroxide fluorochromes were similarly elevated in all atherosclerotic tissue (4.159 +/- 1.065 vs 3.087 +/- 0.497 fluoro units/g tissue) compared to control (p less than 0.01) with significant elevations in saphenous vein grafts and occlusive aortic disease. Although lipid peroxidation and lipid accumulation occur in close association in atherosclerotic plaque, the role of lipid peroxides in the pathogenesis of atherosclerosis remains to be determined.
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PMID:Evidence for lipid peroxidation in atherosclerosis. 231 93

A technique is described which provides morphologic and quantitative data on the amount of oil red O (ORO) staining in thoracic aortas of rats fed a high cholesterol diet. Samples are stained with ORO, the dye is extracted, and the concentration of ORO in the extract is measured colorimetrically. Wistar rats fed ad libitum either standard chow (control group: n = 15) or chow supplemented with 4% cholesterol, 1% cholic acid, and 0.5% thiouracil (CCT group: n = 23) were maintained on these diets for 1, 3, 6, 9, or 12 months. Plasma cholesterol levels averaged overall 87 and 737 mg/dl for the control and CCT groups, respectively. Animals were killed under anesthesia by perfusion fixation with formalin or glutaraldehyde, and samples of thoracic aorta were stained with ORO. After microscopic study en face and measurement of surface area, the ORO was extracted in chloroform-methanol (2:1). Concentrations of ORO (microM) were determined from a standard curve and expressed as microM/mm2 of aorta. Aortas of CCT animals showed progressive diet- and time-dependent increases in the amount of ORO staining compared to controls. We conclude that this method yields reliable quantitative data applicable to studying atherosclerosis in small animals.
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PMID:Quantitation of oil red O staining of the aorta in hypercholesterolemic rats. 276 15

The effects of plant constituents on lipid metabolism were examined in swine that had been fed for 4 weeks a standard diet containing, in addition, (per kg diet) 3.15 g of the methanol serial solvent fraction garlic bulbs or 3.5 g of the petroleum ether solubles high-protein barley flour or 5 mg of the plant growth regulator, AMO 1618. All treatments suppressed 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and cholesterol 7 alpha-hydroxylase activities. Modest increases in serum triglycerides were associated with significantly increased hepatic lipogenic activities in response to all treatments except that of the barley extract. The methanol solubles of a second lot of garlic were fractionated by HPLC and tested in an avian hepatocyte system. One component, an isoprenoid metabolite, MW 358, suppressed HMG-CoA reductase.
Atherosclerosis 1987 Apr
PMID:Influence of minor plant constituents on porcine hepatic lipid metabolism. Impact on serum lipids. 360 7

Hepatic beta-hydroxy-beta-methylglutaryl CoA (HMG-CoA) reductase, cholesterol 7 alpha-hydroxylase (7 alpha-hyd), and fatty acid synthetase (FAS) activities and cholesterol levels were determined in chicks fed isonitrogenous corn- and high-protein barley flour (HPBF) based diets. HMG-CoA reductase (-27%), 7 alpha-hyd (-30%), and serum cholesterol (-13%) were reduced, whereas FAS increased (28%) in comparison to a corn-based (control) diet. fractions obtained by serial extractions of HPBF with solvents of increasing polarity were fed at levels equivalent to 20% HPBF in a corn-based diet to female White Leghorn (WHL) chickens for 3 weeks. A petroleum ether-soluble fraction of HPBF produced 3 effects: an increase in body weight (18%), a strong suppression of HMG-CoA reductase (-36%) and FAS (-40%) accompanied by decreases in serum triglyceride (-9%) and cholesterol levels (-23%). The methanol-soluble fraction produced a significant suppression of HMG-CoA reductase (-49%) and serum cholesterol level (-29%), and an increase in FAS activity (95%). These effects were duplicated in 7-week-old broiler chickens which also showed a significant decrease in chol-LDL (low density lipoprotein) levels by these fractions. The factor(s) lowering serum cholesterol concentration was about equally divided between the polar and nonpolar fractions, and each was significantly more effective than the 20% HPBF in the corn-based diet. The observed effects on lipogenesis and cholesterogenesis might be attributed to a number of chemical constituents of HPBF, but cannot be attributed to the water-insoluble plant fibers.
Atherosclerosis 1984 Apr
PMID:Suppression of cholesterol biosynthesis by constituents of barley kernel. 672 4

Four cases of basal ganglia infarction demonstrated by radionuclide brain imaging are presented. Bilateral basal ganglia infarctions in two patients were probably related to methanol intoxication and meningoencephalitis, and unilateral basal ganglia infarctions in two other patients were presumably due to cerebral atherosclerosis and/or hypertension. Various causes and mechanisms of basal ganglia infarction as well as positive findings of radionuclide brain imaging are briefly reviewed.
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PMID:Basal ganglia infarction demonstrated by radionuclide brain imaging. 675 40

Calcified atherosclerotic aorta was examined for proteolipid capable of nucleating apatite, the crystal species of aortic calcification. Appropriate tissue pieces were decalcified with dilute formic acid and extracted with chloroform-methanol. Lipid fractionation yielded proteolipid which, upon incubation in metastable calcium phosphate solution, induced apatite crystallization. The proteolipid was partially characterized as a hydrophobic protein, acidic phospholipid complex. It resembles the nucleator previously demonstrated for bone matrix calcification.
Atherosclerosis 1980 Feb
PMID:Calcification by proteolipid from atherosclerotic aorta. 735 56

Oxidatively modified LDL (oLDL) is thought to play a key role in the pathogenesis of atherosclerosis. We have studied Cu(2+)-induced peroxidation reactions of LDL and have elucidated the sequence of events which subsequently occur within LDL particles by 1H-NMR spectroscopy. Studies of chloroform/methanol extracts show that LDL arachidonate is oxidised by Cu2+ at a higher rate and to a greater extent than linoleate, giving isomeric hydroperoxides with predominantly trans,trans double-bonds, whilst only cis,trans isomers were detected as intrinsic hydroperoxides in control LDL samples. These intrinsic hydroperoxides were not degraded during peroxidation, suggesting that they are not involved in the initiation of Cu(2+)-induced peroxidation. Aldehydes arising from the decomposition of hydroperoxides were also detected, as well as saturated fatty acids which were released into the external aqueous medium. Decomposition pathways of the two major isomeric hydroperoxides are discussed. Cu(2+)-induced oxidation of LDL cholesterol appears to occur only after hydroperoxide breakdown, with esterified cholesterol being oxidised to a greater extent than free cholesterol. Phospholipid hydrolysis appeared to parallel the peroxidation of arachidonic acid, and the released lysophosphatidylcholine may become associated with apoB. These results suggest that hydroperoxide breakdown (probably in phospholipids) may be a key event in the peroxidation process, leading to the oxidation of cholesterol and propagation into the core of LDL.
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PMID:Copper-induced LDL peroxidation investigated by 1H-NMR spectroscopy. 776 90


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