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)

Senile aortic amyloidosis in 224 autopsy cases over 40 years was investigated comparing cardiac and pancreatic amyloidosis in them. A total of 176 cases of aortic amyloidosis was found for an average incidence of 79%. Under the 5th decade the incidence was 51% and it rose sharply with age and reached 95% in over the 8th decade. The incidence of cardiac amyloidosis also increased with age, but it was always higher in the aorta. Aortic and cardiac amyloid were both positive in the DMAB method for tryptophan. The major part exposed to amyloidosis in the aorta was the media. The medial amyloid consisted of numerous minute deposits and had no relation to atherosclerosis. Some comments about the pathogenesis of senile amyloidosis were also mentioned.
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PMID:Pathological study on amyloidosis--relationship of amyloid deposits in the aorta to aging. 67 43

The structural and compositional changes occurring during in vitro chemical modification of apolipoprotein B-100 (apo B), the apolipoprotein component of low density lipoproteins (LDL), were investigated in this study. The functional properties of chemically modified apo B and especially its potential to induce accumulation of cholesterol esters in macrophages were related to the structural changes of apo B. Acetylation, maleylation or malondialdehyde conjugation did not significantly affect the lipid composition of LDL. However, the unsaturated cholesteryl esters content, especially that of cholesteryl arachidonate was significantly decreased through Cu-oxidation. The number of reactive lysine residues in apo B was decreased by Cu-catalyzed LDL oxidation, acetylation, maleylation and by malondialdehyde conjugation. The number of free cysteines decreased from six in native apo B-100 to three in Cu-oxidized LDL. The tryptophan fluorescence intensity decreased most in malondialdehyde-conjugated LDL and in Cu-oxidized LDL, compared with acetylated and maleylated LDL. The secondary structure of native and chemically modified LDL was measured by attenuated total reflection infrared spectroscopy and by circular dichroism. No significant changes were observed in the secondary structure of any of the modified LDL. These data suggest that neither acetylation, malondialdehyde treatment or even Cu-oxidation substantially altered the secondary structure of apo B, in spite of significant modifications in the primary structure. Incubation of chemically modified LDL with J774 macrophages induced an accumulation of cellular cholesteryl esters and foam cell formation. The highest cholesterol accumulation was induced after malondialdehyde treatment of LDL. These data suggest that the cellular uptake and accumulation of modified LDL is not modulated by changes in the apo B structure. Rather it seems dependent upon the net charge of the apo B protein and probably involves the modification of critical lysine residues.
Atherosclerosis 1992 Dec
PMID:Structural and functional properties of apolipoprotein B in chemically modified low density lipoproteins. 146 63

High plasma cholesterol levels and plasma lipid peroxidation are associated with atherosclerosis. The effect of excessive dietary tryptophan on plasma lipid peroxidation was studied in rats fed a diet containing soybean oil (control), as well as an atherogenic diet, containing coconut oil and cholesterol. Feeding the atherogenic diet resulted in a 5-fold increment in plasma cholesterol concentration with no significant effect of the tryptophan supplementation. The plasma obtained from the hypercholesterolemic rats exhibited a 67% increased lipid oxidation (measured as thiobarbituric acid reactive substances) in comparison to normocholesterolemic plasma. Dietary tryptophan supplementation increased plasma lipid peroxidation by 9 and 21% in the control and in the hypercholesterolemic animals, respectively. Similarly, the excessive dietary tryptophan enhanced macrophage cholesterol esterification rate by 40 and 38% following cell incubation with the plasma obtained from the control and from the hypercholesterolemic animals, respectively. Since tryptophan is the precursor of serotonin we have measured urine concentration of 5-hydroxyindoleacetic acid (5HIAA), the metabolite of serotonin, and found 22 and 118% elevation in 5HIAA in the tryptophan fed control and hypercholesterolemic rats, respectively. The direct effect of tryptophan and serotonin on in vitro lipid peroxidation was also studied. Low density lipoprotein (LDL) was peroxidized by incubation with copper ions in the presence of tryptophan or serotonin. Serotonin was shown to enhance LDL peroxidation whereas tryptophan had no effect on LDL peroxidation. We conclude that excessive dietary tryptophan may be atherogenic since it enhanced plasma lipid peroxidation in hypercholesterolemic rats and increased macrophage uptake of plasma cholesterol. These effects are probably associated with increased plasma concentration of serotonin following the consumption of a tryptophan supplemented diet.
Atherosclerosis 1991 May
PMID:Excessive dietary tryptophan enhances plasma lipid peroxidation in rats. 171 63

An electron spin probe study was made of the effect of lipid peroxidation (LPO) on the structure of surface proteolipid layer of human serum low-density lipoproteins (LDL). The results obtained with a positively charged spin label and stearic acid spin probes with doxyl labels at positions 5, 12, and 16 revealed that LPO caused a decrease in phospholipid molecule mobility both in the region of polar heads and in the region of acyl chains till the depth of at least 1.7 mm from water-lipid interface. Under relatively high levels of oxidation (more than 6 mumol MDA/g LDL phospholipid) the polarity of lipid phase increased. The decrease in efficiency of tryptophan fluorescence quenching by nitroxide fragments incorporated in hydrophobic regions at the depth of approximately 2 nm from water-lipid interface indicated that lipid-protein interaction was disturbed as a result of oxidation of LDL lipids. In addition, the LPO-induced modification of apo-B, the main protein of LDL, was examined with maleimide spin label. LPO led to increase in mobility of strongly immobilized maleimide labels and in the number of weakly immobilized ones. Oxidized LDL revealed decreased ability to incorporate spin-labeled steroid (androstane) as compared to native ones. LPO-induced structural changes of LDL surface are supposed to be a reason of enhanced accumulation of cholesterol in human monocytes during their incubation with oxidized LDL. The cholesterol content in red cells was shown to be directly correlated to MDA content in apo-B containing lipoproteins but not in whole serum. Our findings suggest that free radical modification of serum lipoproteins but not solely an increased level of LPO products in blood is one important cause for cholesterol accumulation in cells and, apparently, for their transformation into foam cells during atherosclerosis.
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PMID:Free radical modification of lipoproteins and cholesterol accumulation in cells upon atherosclerosis. 184 66

In this study, the fluorescent morphological structures in normal coronary artery, normal aorta, and atherosclerotic aorta were histochemically identified and spectroscopically characterized in situ using ultraviolet-excited microspectrofluorimetry. Excitation wavelengths of 290 nm and 310/312 nm were employed to observe two distinct fluorescence bands, with peak emission wavelengths near 335 nm and 380 nm, respectively. Emission of the short wavelength 335 nm band, previously assigned to tryptophan residues in tryptophan-containing proteins, was observed from all the morphological structures in the vessel walls and was isolated in groups of smooth muscle cells in aorta and coronary artery media. The long wavelength 380 nm band was assigned to distinct fluorophores associated with the structural proteins collagen and elastin and was observed in collagen fibers and elastic fibers, respectively. The corresponding morphological structures in normal aorta, normal coronary artery, and atherosclerotic aorta exhibited similar fluorescence lineshapes. In atherosclerotic plaque, a distinct fluorescence band, peaking near 370 nm, was observed in the emission from both ceroid granules and necrotic core. Using a simple, quantitative model, differing contributions of collagen, elastin, and tryptophan-containing protein fluorescence were shown to account for over 95% of the emission from the intima, media, and adventitia layers of non-necrotic aorta and coronary artery.
Atherosclerosis 1991 May
PMID:Characterization of the fluorescent morphological structures in human arterial wall using ultraviolet-excited microspectrofluorimetry. 187 5

A survey shall be given on the physiological, pathophysiological and pharmacotherapeutic backgrounds of the biogenic amine 5-hydroxytryptamine (serotonin; 5HT), to be preceded by a few historical remarks. 5HT is biosynthesized from L-tryptophan via hydroxylation and subsequent decarboxylation. 5HT is predominantly found in enterochromaffin cells, platelets and in various structures of the central nervous system. Its concentration in circulating blood is low and probably subthreshold. Whereas the physiological role of 5HT is rather unclear, 5HT appears to play a relevant role in certain psychiatric disorders, in migraine and the carcinoid syndrome. Its role in essential hypertension remains uncertain. However, 5HT appears to contribute to and to exacerbate the damage to blood vessels which were already predamaged by atherosclerosis, diabetes mellitus or possibly old age as such. A major breakthrough in the pharmacology of the serotonergic system was achieved by the discovery of several subtypes of 5HT receptors, with a corresponding collection of selective agonists and antagonists towards these receptor subtypes. This development is the basis of various drugs which interact with the serotonergic system and its receptors, like the various 5HT2 receptor antagonists (of which ketanserin is the prototype), methysergide, pizotifen, urapidil, flesinoxan and a variety of psychoactive drugs. The most important of these drugs and their potential application will be discussed with an emphasis on cardiovascular disorders.
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PMID:Pathophysiological and pharmacotherapeutic aspects of serotonin and serotonergic drugs. 213 70

Eight men were given 2 casein meals, one with and one without a supplement of arginine and glycine, to measure the effect on plasma amino acids, insulin and glucagon. Supplementation resulted in increased levels of plasma glucagon, glycine and arginine, a tendency to decreased insulin and significantly lower insulin/glucagon ratio, tryptophan and tyrosine. The data suggest that insulin and glucagon, which control cholesterol metabolism, respond to dietary and postprandial plasma amino acid levels of arginine and glycine.
Atherosclerosis 1988 May
PMID:Testing a mechanism of control in human cholesterol metabolism: relation of arginine and glycine to insulin and glucagon. 328 27

This volume details the history of vitamin B6, its chemistry and biochemistry, methods for the assessment of vitamin B6 status, and the clinical chemistry of the vitamin. Since its discovery and synthesis over 40 years ago, vitamin B6 has been implicated in a number of disease states. All approaches to the assessment of vitamin B6 status--direct measurement of blood levels, measurement of the excretion rate of the vitamin, measurement of the metabolites or abnormal metabolic products resulting from a deficient state, or measurement of some other process dependent on the concentration of the vitamin in the body--have significant technical or physiological problems. Dietary allowances vary for different age groups and situations. In the US, the National Academy of Sciences has recommended a daily dietary allowance of 2.2 mg for young adult males and 2.0 mg for young adult females. Additional allowances have been suggested for women during pregnancy and lactation, but not for users of oral contraceptives (OCs). Vitamin B6 deficiency can be either exogenous (when intake falls below the recommended dietary allowance) or conditioned (in cases where the physiologic requirement for the vitamin is higher than the dietary allowance). Conditioned deficiency arises in the following situations: defective intestinal absorption, defective cellular and intercellular transport, and impaired oxidtion or phosphorylation mechanisms in vitamin B6 metabolism. Studies aimed at assessing the abnormal tryptophan metabolism observed in some OC users have produced conflicting results. It appears that severe depression and impairment of glucose tolerance are the only important abnormalities encountered in OC users related to vitamin B6 deficiency. Abnormalities of tryptophan metabolism have been noted in patients with rheumatoid arthritis, some malignant diseases, liver disease, diabetes mellitus, atherosclerosis, and hyperkinetic syndromes.
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PMID:Clinical chemistry of vitamin B6. 639 13

In a material of 74 elderly patients with cerebral symptoms, most of them on account of atherosclerosis, deficiency of pyridoxal phosphate is uncommon: only ten had extremely low plasma levels. Nine of the patients had rather high levels of serum tryptophan. This might depend upon poor metabolization when pyridoxal phosphate is available in insufficient supply. In addition mean values are given for tryptophan, tyrosin and serotonin in this group of patients.
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PMID:Pyridoxal phosphate, tryptophan, and tyrosine in blood and cerebrospinal fluid in elderly patients. 651 67

Low density lipids of the atherosclerosis-unaffected human aorta, unlike plasma lipoproteins belonging to the same class, contain lipid peroxidation products in the superficial layer. The viscosity of the lipid phase of the aorta and blood plasma is the same. In protein of aorta lipoproteins, tryptophan residues are outside the particle whereas in plasma lipoproteins, they are buried deep in the lipid phase. The data on energy transfer to the probes provide evidence in favour of the fact that in aorta lipoproteins, protein is lying on the particle surface in a thicker layer and occupies a 2-times lesser area than in plasma lipoproteins.
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PMID:[Spatial organization of low density lipoproteins of the human aorta (study using fluorescent probes)]. 662 29


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