Several parameters of lipoprotein metabolism were examined in 38 men with primary hypertriglyceridemia (phenotype IV). Family investigation showed that 17 men had familial combined hyperlipidemia (FCH), seven had familial hypertriglyceridemia (FHT), and 14 had unclassified hypertriglyceridemia (UNC). In all three groups, plasma high density lipoprotein (HDL) cholesterol and the concentrations ...

An unusual lipoprotein was detected and purified from the blood of some members of a large colony of baboons, Papio sp. This lipoprotein was found to be similar to human lipoprotein a in all respects and is therefore termed lipoprotein a. Baboon lipoprotein a had a density of 1.052 g/ml ...

Elevated activity of 3-hydroxy-3-methyglutaryl coenzyme A reductase (HMG-CoA reductase) was observed in the rabbit ovary and corpus luteum during pregnancy. Based on this study, it was proposed that de novo cholesterol synthesis rather than the uptake of exogenous plasma cholesterol (lipoproteins) was of primary importance in providing steroid substrate for ...

Liver regeneration after partial hepatectomy was used as an experimental model for studying mammalian cell division and replication. The rate of cell proliferation in this hyperplastic model was correlated with hepatic de novo synthesis of cholesterol, with the hexose monophosphate shunt pathway of glucose metabolism, and with serum lipoproteins. An ...

The effect of plant lectins on low density lipoprotein metabolism was studied in isolated human adipocytes. Concanavalin A (0.1 mg X mL-1) resulted in 3-5 fold increase in [125I]-low density lipoprotein uptake in isolated human adipocytes but [125I]-low density lipoprotein degradation was not significantly affected. Adipocytes pre-incubated with alpha-methyl-D-mannopyranoside showed ...

The effect of experimental hypothyroidism on the catabolism of plasma lipoproteins and on the expression of low density lipoprotein receptors by the liver was investigated in rats made hypothyroid by surgery. The animals developed mild hypercholesterolemia, mainly due to an increase of plasma low density lipoprotein, while other lipoprotein classes ...

This article describes the assignment of dyslipoproteinemia (DLP) in several free-living North American populations and presents mean lipid and lipoprotein levels for each type. Dyslipoproteinemic phenotypes were assigned by a modified version of the National Institutes of Health (Fredrickson) phenotyping system. Criteria for assigning phenotypes included age- and sex-specific 5th ...

Severe liver disease may be associated with a reduction in plasma concentration of high density lipoprotein and an impairment of plasma cholesterol esterification. These changes were confirmed in two patients with severe acute on chronic alcoholic liver disease. In five additional patients with biopsy-proven clinically compensated cirrhosis, there was minimal ...

A large pedigree (N = 356) with a high prevalence of heart disease and associated adverse lipoprotein phenotype was studied. The adverse lipoprotein phenotype is characterized by both low levels of high-density-lipoprotein cholesterol (HDL-C) alone (16.3%) and in combination with other adverse lipoprotein levels (12.8%). In all, 44.2% of all ...

Intravenous administration of Lipofundin-S oil, in the rat induces arteriosclerotic lesions within several days. Changes in lipids and lipoproteins were studied by lipid electrophoresis, ultracentrifugation and gel filtration. One hour after injection of Lipofundin, a dramatic increase occurred in triglycerides and phospholipids, reflecting the composition of the lipid emulsion. During ...

Density gradient centrifugation was used to characterize the lipoprotein distribution of rhesus monkeys and human subjects with normal and elevated cholesterol levels. The lipoprotein profile of control monkeys differed from that of normal humans in that their density distribution as a whole was shifted to lower density. The most striking ...

We sought to clarify whether or not hyperlipoproteinemia induces auditory dysfunction. In so doing, we studied the general states and cochlear pathologies of guinea pigs after the administration of a hyperlipid diet for 3 months. Serum biochemistries indicated marked elevations of cholesterol, high density lipoprotein (HDL)-cholesterol and low density lipoprotein ...

The distribution of cholesterol (C), triglycerides (TG), phospholipids (PL) and protein in the different lipoproteins was studied in male Wistar rats under 2 conditions: control and 2 months after portacaval anastomosis (PCA). PCA decreased the levels of cholesterol and the other components in chylomicrons (-90%), very low density lipoproteins (-65 ...

The hyperlipidemia observed in familial hypercholesterolemia can be reduced by portacaval anastomosis. We report the effects of a portacaval shunt on hepatic morphology and biosynthetic pathways crucial to hepatic cholesterol homeostasis in homozygous receptor-negative familial hypercholesterolemia. Portacaval anastomosis was associated with a dramatic change in hepatocyte morphology, 28% reduction in ...

Total and low density lipoprotein cholesterol concentration reduction in patients with markedly increased levels of these substances, leads to a decline in the incidence of myocardial infarction and death. A unique cholesterol-rich lipoprotein, lipoprotein Lp(a), has been identified which not only can be confused with low density lipoproteins, but has ...

Five methods for the quantification of low-density-lipoprotein cholesterol were compared: ultracentrifugation, electrophoresis, precipitation with polyvinyl sulfate or heparin, and an indirect calculation procedure (Friedewald formula). Excellent agreement of results was obtained with all procedures for 49 of 51 sera. Discrepancies were as much as 1.69 g/L for the remaining two ...

The effect of a triphasic combination of ethinyl estradiol and levonorgestrel upon various lipoprotein parameters was compared to that of a preparation that contained ethinyl estradiol and desogestrel on days 6, 11, 21, and 28 of a control cycle, the third cycle of treatment with either ethinyl estradiol/levonorgestrel or ethinyl ...

Plasma lipoproteins from 5-week old male chickens were separated over the density range 1.006-1.172 g/ml into 22 subfractions by isopycnic density gradient ultracentrifugation, in order to establish the distribution of these particles and their constituent apolipoproteins as a function of density. Lipoprotein subfractions were characterized by electrophorectic, chemical and morphological ...

Gemfibrozil (Lopid) is a new plasma lipid-regulating drug that decreases very low and low density lipoprotein (VLD/LDL) and increases high density lipoprotein (HDL) concentrations in man. The present experiments tested the effects of gemfibrozil on plasma lipoproteins and apolipoproteins in rats fed high fat/high cholesterol diets. Compared to chow-fed rats, ...

beta beta'-Methyl-substituted alpha, omega-dicarboxylic acids (MEDICA) of C14-C18 chain length were found to inhibit liver lipid synthesis in the rat in vivo. Maximum inhibition was observed with MEDICA 16 amounting to a 50% decrease in fatty acid and cholesterol biosynthesis in the presence of 0.07 and 0.015% (w/w) of the ...

Levels of high-density lipoprotein cholesterol were found to be significantly lower in 5 men with multi-infarct dementia than in 12 men with senile dementia of the Alzheimer type. The large difference between the groups suggests that levels of high-density lipoprotein cholesterol may be useful in differential diagnosis of these two ...

Male mice of two inbred strains, C57BR/cdJ and CBA/J, were maintained either on an atherogenic diet rich in cholesterol (5%) and saturated fat (30%) or on a control Purina Laboratory Chow diet. After 3 weeks on a 90% atherogenic/10% chow diet, the C57BR/cdJ mice showed a fivefold increase in plasma ...

The concentration of low density lipoprotein in human plasma depends on the balance between its rates of synthesis and catabolism. Although both processes appear to be independently regulated they occur side by side in the liver and may be linked via the activity of the high affinity low density lipoprotein ...

The interactions between radiolabeled, human plasma lipoproteins and elastin derived from bovine ligamentum nuchae were investigated using a washout technique. The interaction was characterised by Ki, a coefficient of irreversible binding, and Kr, the reversible partition coefficient. For both low-density lipoproteins (LDL) and high-density lipoproteins (HDL) the Ki values decreased ...

The effects of intramuscular injections of adrenocorticotropin (ACTH) or short-term exposures to high environmental temperature (44 to 46 C) were determined on the relative amounts of lipoproteins in the serum of 6 to 7-week-old White Rock chickens. In addition, the influence of the sex of the bird and fasting vs. ...

In the present review, the role of lipid disturbances is evaluated as a risk factor in the pathogenesis and the potential acceleration of atherosclerosis in uremic patients undergoing long-term hemodialysis. The alteration in high density lipoprotein composition with a decrease in high density lipoprotein cholesterol but a normal apoprotein AI ...

Serum lipids, very low in the fetus and at birth, increased rapidly after the first feeding. Cholesterol was mainly in the free form. Esterified cholesterol rose rapidly, but free cholesterol remained in high proportions (30%) until after weaning. Very high phospholipid concentrations show that triglycerides are not the only major ...

Standardization of lipid and lipoprotein measurements is of concern to laboratories that serve pediatric as well as adult populations, since preventive measures taken during pediatric years can help control atherosclerotic cardiovascular problems that can arise during adult years. Multiple analytical and physiologic problems that exist inherently in the lipids and ...

The metabolic fate of very low density lipoprotein can be examined by following the transit of its apolipoprotein B moiety through the delipidation cascade, which leads to low density lipoprotein. In this study we have used cumulative flotation ultracentrifugation to follow the metabolism of various lipoprotein subclasses that participate in ...

Six multiparous Holstein cows ranging from 7 to 19 wk postpartum were in a switchback design to determine effects of feeding high grain diets on lipoprotein concentration and composition in blood. Percents concentrate, alfalfa haylage, and corn silage of control and high grain diets were 50, 83; 25, 9; and ...

The purpose of the present investigation was to determine the effect of various lipoproteins on the rate of cholesterol synthesis of human fetal liver cells maintained in culture. This was accomplished by measuring the rate of incorporation of tritium from tritiated water or carbon 14-labeled acetate into cholesterol in human ...

We evaluated three precipitation methods for determination of low-density lipoprotein cholesterol in serum and an indirect method involving the Friedewald formula (Clin Chem 18: 499-502, 1972) by comparison with results by ultracentrifugation. The results of all methods for 83 sera, including 59 hyperlipidemic type IIA, IIB, and IV sera agreed ...

Lipoprotein concentrations were measured in 31 post-menopausal women during 1 yr of treatment with Trisequens, a natural oestrogen-progestogen preparation. Serum triglyceride, high density lipoprotein and very low density lipoprotein cholesterol concentrations did not change significantly, but low density lipoprotein cholesterol concentrations fell over the first 6 mth. After 1 yr ...

Heparin-Sepharose affinity chromatography resolved rat lipoproteins isolated in the density range 1.019-1.063 g/ml into two distinct fractions. The first, which eluted with 150 mM NaCl, was shown by immunodiffusion and by polyacrylamide gel electrophoresis to contain predominantly apo E. On this basis the major lipoprotein present is identified as high ...

Changes in circulating lipoproteins, which may be related to the risk for atherosclerotic vascular disease, were studied in a control group and in two groups of 24 or 26 women using different preparations of low-dose oral contraceptives for 3 months. One preparation contained 150 micrograms levo-norgestrel and 30 micrograms ethinylestradiol ...

A method is described for the isoelectric focusing (IEF) of lipoproteins on thin films of agarose. Within a pH gradient of 4.60-5.30 both high-density lipoproteins 2 and 3 (HDL2 and HDL3) are resolved into more than 10 fractions which could be stained either for protein or for lipids. The isoelectric ...

Rats were injected intravenously with cholera toxin, a potent stimulator of adenylate cyclase, and lipoprotein lipase was determined in various organs and plasma. 16 h after cholera toxin injection, lipoprotein lipase activity increased 2-6-fold in heart, diaphragm and lung and decreased to one-third in adipose tissue. An increase in lipoprotein ...

Female Wistar rats (5 and 11 weeks old) were either left intact or ovariectomized. Animals of each age- and treatment-group were either ad lib.-fed or undernourished for 4 weeks. The bodies of all animals were analysed for protein and fat and the weights, lipid synthesis rate and lipoprotein lipase (EC ...

Lipoprotein concentration and composition before and after Intralipid infusion were investigated in seven adult surgical patients receiving continuous total parenteral nutrition. Plasma samples were obtained prior to parenteral alimentation, after 7 days of glucose/amino acid solution without Intralipid, and again following 5 days of daily Intralipid. Cholesterol, triglyceride, protein, and ...

The purpose of this study was to investigate the effects of probucol on the plasma levels of low density lipoproteins in rabbits and whether the resulting decrease of low density lipoproteins was related to the effects of probucol on the expression of lipoprotein receptors. Probucol administration effectively lowered plasma cholesterol ...

In normal dogs fed diets containing 1% cholesterol and 30% saturated fat, cholesterol concentration increased in plasma, cardiac lymph, and peripheral lymph. The increase in cardiac lymph cholesterol always exceeded that of peripheral lymph. At plateau, LDL cholesterol increased in plasma and peripheral lymph but not in cardiac lymph; HDL2 ...

The potential contribution of the metabolism of absorptive lipoproteins to effects of dietary cholesterol and saturated (versus polyunsaturated) fat on plasma lipids and lipoproteins was studied in rats. Recipients were fed either a commercial stock diet, a low fat/cholesterol-free semipurified diet with a neutral P/S ratio, or one of two ...

Because of the controversy over the best method for assaying high density lipoprotein (HDL) cholesterol in the clinical laboratory, a commonly used phosphotungstate method for precipitating low density and very low density lipoproteins (LDL and VLDL) was compared with a recently recommended dextran sulfate precipitation method. The accuracy and precision ...

The aqueous humor of the cow and human was examined for the presence of lipids and lipoproteins. Whole aqueous humor collected from cow eyes within 30 min after slaughter contained about 1 micrograms/ml of cholesterol and phospholipid. Upon fractionation of bovine aqueous into various density ranges following sequential ultracentrifugations , ...

Dextran sulfate was covalently bound to cellulose beads (LA01) and used as the specific sorbent of apolipoprotein B-containing lipoproteins. The binding profiles of very low density, low density, and high density lipoproteins to the material were consistent with simple Langmuir adsorption isotherms. Although the affinities of all lipoproteins for the ...

Rat liver microsomes were extracted with acetone, and a microsomal powder preparation was obtained. The cholesterol 7 alpha-hydroxylase activity of acetone powder was linear with time, the amount of protein, and the amount of cholesterol in human or rat serum. Unesterified lipoprotein cholesterol was also an effective substrate, and the ...

A large pedigree was ascertained through cases of early myocardial infarction. High density lipoprotein cholesterol and apolipoproteins A-I and A-II were measured on family members. Likelihood analysis, using the polygenic/major gene mixed model, provided no evidence that major loci play a role in determining the levels of any of the ...

Lipoprotein lipase activity in adult rats was investigated in animals subjected to cold and to different hormonal treatments. In contrast to changes in tissue wet weight and total protein content, which showed a lag time of about 1 day, lipoprotein lipase activity was markedly (fourfold) increased after only 4 h ...

Kinetic studies were performed incubating lipoprotein lipase and hepatic triacylglycerol lipase from human postheparin plasma with triacylglycerol-rich lipoproteins from two patients with apolipoprotein C-II deficiency. These lipoproteins differed in their lipid and apolipoprotein composition from normal very-low-density lipoproteins and chylomicrons. The addition of isolated apolipoprotein C-II and normal or apolipoprotein ...

Induced circular dichroism (CD) of beta-carotene has been used to study the physical state in the cores of three classes of triglyceride-rich lipoproteins from human serum: intermediate-density lipoproteins (IDL) (1.006 less than d less than 1.019 g/mL) and subfractions of the d less than 1.006 g/mL lipoproteins of beta and ...