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

The effect of nicotinic acid was investigated in Rhesus monkeys. Subcutaneous injections of nicotinic acid lower the plasma very low density lipoprotein (VVLDL) and low density lipoprotein (HDL) concentration. The fall in LDL concentration is not accompained by any change in the lipid or protein composition of either lipoprotein. Analysis by Sephadex gel chromatography and polyacrylamide-gel electrophoresis showed that the proteins of monkey VLDL and LDL are qualitatively similar to those of human VLDL and LDL, although there are differences in the proportions of the various proteins present in the two species. Subcutaneous injections of nicotinic acid diminish the maximum incorporation of 14C from [14C]threonine into VLDL and LDL apoproteins, but have no effect on incorporation into albumin or HDL apoprotein. Peak incorporations into the apo-B and apo-C of VLDL are diminished to about equal extents by nicotinic acid. Comparison of the amount of 14C lost from apo-B of VLDL after the peak of incorporation, with that gained by apo-B of LDL during the same period, suggests that some of the circulating apo-B of LDL IS DERIVED FROM SOURCES OTHER THAN CIRCULATING VLDL.
Atherosclerosis
PMID:The effect of nicotinic acid on the metabolism of the plasma lipoproteins of rhesus monkeys. 16 24

Cholesterol feeding in miniature swine resulted in a hypercholesterolemia with a distinctive hyperlipoproteinemia and the subsequent development of atherosclerosis. Alterations in the type and distribution of plasma lipoproteins induced by cholesterol feeding were as follows: (a) the occurrence of beta-migrating lipoproteins (B-VLDL) as well as very low density lipoproteins in the d less than 1.006 ultracentrifugal fraction; (b) an increased prominence of the intermediate lipoproteins (d = 1.006-1.02); (c) an increased prominence of low density lipoproteins; and (d) the occurrence of a distinctive lipoprotein with alpha mobility which was referred to as HDLc (cholesterol induced). Characterization of the various plasma lipoproteins included chemical composition, size by electron microscopy, and apoprotein content. The B-VLDL resembled the beta-migrating lipoproteins of human Type III hyperlipoproteinemia and contained a prominent protein equivalent to the arginine-rich apoprotein in addition to the B apoprotein, apo-A-I, and the fast-migrating apoproteins (apo-C). The HDLc were rich in cholesterol, ranged in size from 100 to 240 A in diameter, and contained the arginine-rich apoprotein and apo-A0I but lacked the B apoprotein. The arginine-rich apoproteins isolated from B-VLDL and HDLc by gel chromatography were similar in amino acid analyses, with glutamic acid as their amino-terminal residue. The occurrence of a spectrum of cholesterol-rich lipoproteins which contained the arginine-rich apoprotein with the occurrence of accelerated atherosclerosis suggested an interesting, although speculative, association.
 ...
PMID:Swine lipoproteins and atherosclerosis. Changes in the plasma lipoproteins and apoproteins induced by cholesterol feeding. 16 8

We studied the metabolism of different classes of lipoprotein in squirrel monkeys and rabbits. Lipoproteins were labeled in vivo in donor animals with (3H)leucine and (3H)cholesterol. The rate of disappearance from plasma of recipient squirrel monkeys of the protein moiety of the very low density lipoproteins was rapid, that of high density lipoproteins slow, and the rate for low density lipoproteins was intermediate. The fractional turnover of the apoprotein of low density lipoproteins was slightly reduced in hyperlipidemic monkeys, but the absolute rates of synthesis and catabolism were increased. Hyperdipidemia in rabbits resulted in a dramatic reduction in the fractional catabolic rate of low density lipoprotein apoprotein. Hyperlipidemia in the donors of biosynthetic low density lipoproteins also influenced the rates of catabolism in rabbits. We showed the cycloheximide that although there was recycling of (3H)leucine into other proteins, the reutilization of leucine from low density lipoproteins for nascent low density lipoproteins was not significant. In most tissues the ratio of cholesterol:protein radioactivity was much greater than that for plasma 24 h after administration of labeled low density lipoproteins, but the ratios for aortic intima plus inner media and for plasma low density lipoproteins were similar. The presence of atherosclerosis resulted in a large increase in the apparent uptake of low density lipoproteins by the aortas of rabbits and monkeys.
 ...
PMID:The effects of hyperlipidemia on lipoprotein metabolism in squirrel monkeys and rabbits. 16 56

Plasma lipids and chemical, electrophoretic and electron microscopic properties of VLDL, LDL and HDL are examined in rabbits fed a control diet (group I) or diets containing 1% cholesterol (group II), 1% cholesterol + 5% coconut oil (group III) or 1% cholesterol + 5% corn oil (group IV). The diets II, III and IV resulted in hypercholesterolemia, hypertriglyceridemia and hyperphospholipidemia. The lipid-protein composition of VLDL, LDL and HDL is changed by these diets. There is marked increase in the total cholesterol content of all lipoprotein fractions of the high fat dietary groups II, III and IV. The electrophoretic mobilities of the VLDL and LDL II and III are reduced while the respective mobilities in the corn oil group IV are nearly "normal". In contrast to the control LDL fraction I which is not precipitated by heparin, the LDL fractions of the dietary groups II, III and IV are readily precipitated. The apoprotein pattern of the lipoproteins in polyacrylamide gel differs distinctly between the dietary groups, most bands appearing in group IV. An abnormal stacking of lipoprotein particles in electron micrographs of VLDL, LDL and HDL of groups II and III can be observed. In contrast, these lipoprotein fractions of rabbits of the corn oil group IV have morphological properties that are similar to those of the lipoproteins of the control group. It is suggested that these findings are related to the marked reduction of atherosclerosis in rabbits fed a diet with polyunsaturated fat as compared with rabbits on cholesterol and cholesterol-coconut oil diets.
Atherosclerosis
PMID:Changes in rabbit lipoprotein properties by dietary cholesterol, and saturated and polyunsaturated fats. 16 9

Pig plasma lipoproteins were separted into four density classes (very low density, two low density and high density lipoproteins, VLDL, LDL1, LDL2 and HDL respectively) from 670 ml plasma by ultracentrifugation in a continuous density gradient using the Spinco Ti15 zonal rotor. LDL1 and LDL2 were partly characterised. LDL1 and LDL2 are beta-migrating lipoproteins of different size and hydrated density; they are similar to human LDL2 and LDL3 respectively. Pig plasma contains about twice as much LDL1 as LDL2. LDL1 migrates at Sf 4.9 (modal value), and has a mean diameter of 217 A and a modal density of 1.035 g/ml (range 1.03-1.04 g/ml). LDL2 migrates at Sf 1.8 and has a mean diameter of 195 A and a density of 1.050 g/ml. Both lipoproteins are precipitated by heparin and Mn++ or by dextran sulphate and Ca++. The apoproteins of LDL1 and LDL2 are both largely insoluble in 8 M urea solution. When dissolved in 1% sodium dodecyl sulphate solution and electrophoresed on polyacrylamide gel at pH 7.0, the apoproteins of LDL1 and LDL2 formed a pattern of multiple bands of high molecular weight similar to that obtained from the apoprotein of human LDL. Both LDL1 and LDL2 share a major antigen with each other and with VLDL; in this respect again they resemble human LDL. The amino acid compositions of LDL1 and LDL2 are very similar. We concluded that the apoprotein moieties of pig plasma LDL1 and LDL2 are probably identical, and similar to apoprotein B in human serum. Zonal ultracentifugation has proved to be a rapid and effective method for isolating large quantities of these two lipoprotein classes for further metabolic studies. This method allows rapid bulk preparation of lipoproteins, and provides a record of their distribution and quantity in a continuous density gradient.
Atherosclerosis
PMID:Properties of two pig low density lipoproteins prepared by zonal ultracentrifugation. 17 55

The small molecular weight apolipoproteins of pig very low density lipoprotein were investigated following their separation by gel filtration and ion exchange chromatography. Gel filtration through Sephadex G-200 in 6 M urea, produced essentially the same elution profile to that obtained after filtration of human very low density apolipoprotein. However, separation of the pig Sephadex fraction corresponding to human C proteins on DEAE-cellulose columns revealed the presence of only one major peptide and minor quantities of several others. Some properties of three apparent homogeneous fractions and one heterogeneous DEAE fraction were investigated. Unlike human apoprotein CII apoprotein, none of the pig peptides studied activated cow's milk lipase and sialic acid was not detected in any of the three purified C peptides of pig VLDL. The amino acid compositions of the pig peptides were different to those reported for human C apoproteins. The carboxy terminal residue of the major pig C peptide was shown to be serine. The differences so far revealed between pig and human C peptides need further investigation especially since this animal is regarded as a suitable model for investigating human lipoprotein metabolism and the development of atherosclerosis.
 ...
PMID:Characterisation of the small molecular weight apolipoproteins from pig plasma very low density lipoprotein. 17 51

The effects of C1-719 on plasma lipid and lipoprotein concentrations have been examined in four patients with endogenous hypertriglyceridaemia maintained on an isocaloric diet for a period of 6 months. During therapy (400 mg/day) the mean plasma triglyceride and cholesterol concentrations were reduced by 35% and 15% respectively, while the administration of 800 mg/day reduced these by 49% and 31%. This hypolipidaemic effect was due to a reduction in the circulating level of very low density lipoproteins (VLDL) without a change in their composition. Before treatment the plasma VLDL triglyceride turnover, and FFA flux, were higher than that of normal subjects maintained on a similar diet. The plasma VLDL B-apoprotein turnover was similarly higher than in the controls. Administration of C1-719 decreased the plasma VLDL triglyceride turnover, FFA flux and VLDL B-approtein turnover. The drug reduced the insulin response following a glucose load with some decrease in glucose levels. The results suggest that the increase in plasma triglyceride concentration in patients with endogenous hypertriglyceridaemia is due to increased production of plasma VLDL triglyceride and its apoptein associated with an enhanced supply of FFA for hepatic triglyceride synthesis. C1-719 exerts a hypolipidaemic effect through a reduction of VLDL production, consequent upon inhibition of lipolysis as well as decreased synthesis of the apoprotein carrier. These effects could in part be explained by an improvement in peripheral tissue responsiveness to insulin and decreased exposure of the liver to high levels of insulin. However, a direct effect of the drug on adipose tissue and liver metabolism has to be considered.
Atherosclerosis
PMID:Transport kinetics of plasma free fatty acid, very low density lipoprotein triglycerides and apoprotein in patients with endogenous hypertriglyceridaemia: effects of 2,2-dimethyl, 5(2, 5-xylyoxy) valeric acid therapy. 18 85

Patas monkeys were studied for 2 years on three dietary regimes: (1) commercial chow (control diet); (2) semipurified diet plus lard (fat-fed); and (3) semipurified diet plus lard and cholesterol (cholesterol-fed). The control and fat-fed animals had similar lipoproteins which were equivalent to the human very low density, low density (LDL), and high density lipoproteins. An additional lipoprotein referred to as LDL-II appeared to be equivalent to the human Lp(a). The cholesterol-fed animals developed accelerated atherosclerosis associated with a hypercholesterolemia which was characterized by (1) the appearance of beta-migrating lipoproteins (B=VLDL) in the d less than 1.006, (2) an increase in the intermediate lipoproteins and LDL, and (3) the appearance of LDL-II which contained a prominence of the arginine-rich apoprotein. The arginine-rich apoprotein was also a prominent component of the B-VLDL and intermediate lipoproteins. Characterization of this apoprotein revealed that it contained 11.5 mol % arginine, had a molecular weight of approximately 34 000, and coelectrophoresed with the arginine-rich apoprotein of man, dog, swine, rat, and rabbit.
 ...
PMID:Atherogenic hyperlipoproteinemia induced by cholesterol feeding the Patas monkey. 18

Plasma lecithin: cholesterol acyl transfer (LCAT) rate and concentrations of lipids in plasma and lipoproteins were studied in 107 hyperlipidemic subjects. In all types of hyperlipoproteinemia LCAT rates were higher than in a normolipidemic reference group. LCAT rates were highest in type IV and V. There was a considerable overlap of LCAT rates between type IIa, IIb and reference subjects. The LCAT rate correlated positively with very low density lipoprotein concentration, body mass and excess body mass. Low density lipoprotein concentration correlated positively with the LCAT rate only in the reference group. The high density lipoprotein concentration correlated negatively with the LCAT rate. It was suggested that the LCAT rate in vitro reflects the in vivo turnover of cholesteryl esters as a part of the turnover of apoprotein-B containing lipoprotein complexes in plasma. The results might then indicate an inflow rate of lipoproteins in plasma that is increased in most type IV cases but normal or only moderately increased in type IIa and IIb subjects. Analysing the relations between the LCAT rate and the concentrations of lipids in plasma by multiple regression indicated hypothetically deficiencies of lipoprotein removal from plasma in half of type IIa and one third of type IIb subjects.
Atherosclerosis 1977 Feb
PMID:Lecithin: cholesterol acyl transfer rate in plasma and its relation to lipid and lipoprotein concentrations in primary hyperlipidemia. 18 84

Dogs maintained for 1 year on a semisynthetic diet containing hydrogenated coconut oil and cholesterol developed hypercholesterolemia. In those cases where plasma cholesterol levels exceeded 750 mg/100 ml, the animals also developed severe atherosclerosis. This atherogenic hyperlipoproteinemia was characterized by the presence of beta very low density lipoproteins (B-VLDL), increased levels of low density lipoproteins (LDL), and the occurrence of the HDLc lipoproteins. In all of these cholesterol-rich lipoproteins the arginine-rich apoprotein (ARP) was prominent. Moreover, the HDLc (d = 1.006-1.02) contained the ARP as the only detectable apoprotein. The atherosclerosis involved the abdominal aorta, coronary and cerebrovascular arteries, and many of the peripheral arteries. Histologically, the aortic lesions were characterized by a variable intimal proliferative response and extensive medial lipid deposition. In the peripheral, coronary, and cerebral arteries, the lesions were more extensive and involved primarily the media of the vessel wall, with little intimal reaction in many cases. The correlation between the in vivo disease process and the response of aortic smooth muscle cells (SMC) grown in tissue culture to the various cholesterol-induced lipoproteins was examined. B-VLDL, LDL, and HDLc (but not HDL2) caused a marked accumulation of free and esterified cholesterol in the SMC. The cholesterol accumulation was found to be more extensive in canine SMC than in swine smooth muscle cells or smooth muscle cells of other species in response to a similar lipoprotein cholesterol concentration. The enhanced sterol uptake appeared to be a property of canine smooth muscle cells rather than a property of the canine lipoproteins. These in vitro results may be related to the observed propensity for the development of medical disease that was demonstrated in the in vivo studies.
 ...
PMID:Canine hyperlipoproteinemia and atherosclerosis. Accumulation of lipid by aortic medial cells in vivo and in vitro. 19 82


1 2 3 4 5 6 7 8 9 10 Next >>