Effect of human high density lipoproteins, anti-apolipoproteins CII and CIII, and hydrolysis of very low density lipoprotein (VLDL) cholesterol ester on VLDL catabolism in vitro

1984 ◽  
Vol 121 (3) ◽  
pp. 946-952 ◽  
Author(s):  
B.W. Liu ◽  
B.A. Hynd ◽  
M.L. Kashyap
Keyword(s):  
Cholesterol Ester ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Vldl Cholesterol ◽  
Hydrolysis Of

The interaction of lipolysis products of very low density lipoprotein with plasma high density lipoprotein (HDL): perfusate HDL with plasma HDL subfractions

1987 ◽  
Vol 65 (3) ◽  
pp. 252-260 ◽  
Author(s):  
S. P. Tam ◽  
W. C. Breckenridge
Keyword(s):  
Particle Size ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Density ◽  
Molar Ratio ◽  
High Density Lipoproteins ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Hdl Subfractions ◽  
Apo E

The nature of the interaction of high density lipoproteins (HDL), formed during lipolysis of human very low density lipoprotein (VLDL) by perfused rat heart, with subfractions of human plasma HDL was investigated. Perfusate HDL, containing apoliproproteins (apo) E, C-II, and C-III but no apo A-I or A-II, was incubated with a subfraction of HDL (HDL-A) containing apo A-I and A-II, but devoid of apo C-II, C-III, and E. The products of the incubation were resolved by heparin-Sepharose or hydroxylapatite chromatography under conditions which allowed the resolution of the initial HDL-A and perfusate HDL. The fractions were analyzed for apolipoprotein content and lipid composition and assessed for particle size by electron microscopy. Following the incubation, the apo-E-containing lipoproteins were distinct from perfusate HDL since they contained apo A-I as a major component and apo C-II and C-III in reduced proportions. However, the HDL-A fraction contained apo C-II and C-III as major constituents. Associated with these changes in apolipoprotein composition, the apo-E-rich lipoproteins acquired cholesteryl ester from the HDL-A fraction and lost phospholipid to the HDL-A fraction. The HDL-A fraction maintained a low unesterified cholesterol/phospholipid molar ratio (0.23), while the apo-E-containing lipoproteins possessed a high ratio (0.75) characteristic of the perfusate HDL. The particle size of apo-E-containing lipoproteins (138.9 ± 22.5 Å; 1 Å = 0.1 nm) was larger than the initial HDL-A (126.5 ± 17.6 Å) or the new HDL-A-like fraction (120.9 ± 17.4 Å) obtained following incubation with perfusate HDL. It is concluded that incubation of perfusate HDL containing apo E, C-II, and C-III with plasma HDL subfractions results in the acquisition of apo A-I and cholesteryl esters by the apo-E-containing perfusate HDL and the loss of apo C-II, C-III, and phospholipid to the plasma HDL-A fraction. The process does not appear to be due to fusion of the particles, since the apo-E-containing lipoproteins maintain a cholesterol/phospholipid ratio distinct from the HDL-A fraction. The data provide evidence for a potential mechanism for the formation of HDL-E, an apo-E-containing lipoprotein of HDL size and density, through lipolysis of VLDL.

scholarly journals Association of the Endotoxin Antagonist E5564 with High-Density Lipoproteins In Vitro: Dependence on Low-Density and Triglyceride-Rich Lipoprotein Concentrations

2003 ◽  
Vol 47 (9) ◽  
pp. 2796-2803 ◽  
Author(s):  
Kishor M. Wasan ◽  
Olena Sivak ◽  
Richard A. Cote ◽  
Aaron I. MacInnes ◽  
Kathy D. Boulanger ◽  
...  
Keyword(s):  
Human Plasma ◽  
Human Subjects ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Distribution Profile ◽  
Transfer Activity

ABSTRACT The objective of this study was to determine the distribution profile of the novel endotoxin antagonist E5564 in plasma obtained from fasted human subjects with various lipid concentrations. Radiolabeled E5564 at 1 μM was incubated in fasted plasma from seven human subjects with various total cholesterol (TC) and triglyceride (TG) concentrations for 0.5 to 6 h at 37°C. Following these incubations, plasma samples were separated into their lipoprotein and lipoprotein-deficient fractions by ultracentrifugation and were assayed for E5564 radioactivity. TC, TG, and protein concentrations in each fraction were determined by enzymatic assays. Lipoprotein surface charge within control and phosphatidylinositol-treated plasma and E5564’s influence on cholesteryl ester transfer protein (CETP) transfer activity were also determined. We observed that the majority of E5564 was recovered in the high-density lipoprotein (HDL) fraction. We further observed that incubation in plasma with increased levels of TG-rich lipoprotein (TRL) lipid (TC and TG) concentrations resulted in a significant increase in the percentage of E5564 recovered in the TRL fraction. In further experiments, E5564 was preincubated in human TRL. Then, these mixtures were incubated in hypolipidemic human plasma for 0.5 and 6 h at 37°C. Preincubation of E5564 in purified TRL prior to incubation in human plasma resulted in a significant decrease in the percentage of drug recovered in the HDL fraction and an increase in the percentage of drug recovered in the TRL and low-density lipoprotein fractions. These findings suggest that the majority of the drug binds to HDLs. Preincubation of E5564 in TRL prior to incubation in normolipidemic plasma significantly decreased the percentage of drug recovered in the HDL fraction. Modifications to the lipoprotein negative charge did not alter the E5564 concentration in the HDL fraction. In addition, E5564 does not influence CETP-mediated transfer activity. Information from these studies could be used to help identify the possible components of lipoproteins which influence the interaction of E5564 with specific lipoprotein particles.

scholarly journals Repercussões da cirurgia bariátrica na qualidade de vida, no perfil bioquímico e na pressão arterial de pacientes com obesidade mórbida

2018 ◽  
Vol 25 (3) ◽  
pp. 284-293
Author(s):  
Lucas Silva Franco de Oliveira ◽  
Mauro Lúcio Mazini Filho ◽  
Juliana Brandão Pinto de Castro ◽  
Henrique Menezes Touguinha ◽  
Patrick Costa Ribeiro Silva ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density Lipoproteins ◽  
High Density ◽  
High Density Lipoproteins ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Sf 36

RESUMO A indicação da cirurgia bariátrica (CB) para perda de peso e redução de comorbidades associadas à obesidade é crescente. O objetivo do presente estudo foi analisar as repercussões da CB na qualidade de vida (QV), no perfil bioquímico e na pressão arterial (PA) de indivíduos obesos mórbidos em três momentos distintos: um mês antes, três meses depois e seis meses após a CB. Participaram da pesquisa 42 indivíduos com obesidade mórbida do programa de CB de um hospital da cidade de Juiz de Fora - MG, os quais foram aleatoriamente divididos em grupo intervenção (GI, n=21) e grupo controle (GC, n=21). O GI sofreu intervenção cirúrgica e o GC foi orientado a manter os afazeres diários usuais durante todo período do estudo, além de receberem acompanhamento nutricional. Foram avaliados a QV, o perfil bioquímico e a PA através do instrumento SF-36, do exame laboratorial de sangue obtido no prontuário dos pacientes e do esfigmomanômetro e estetoscópio, respectivamente. Os resultados demonstraram redução nas variáveis bioquímicas High-density lipoproteins (HDL), Low-density lipoproteins (LDL), Very Low-Density Lipoprotein (VLDL), colesterol, triglicerídeos, hemoglobina glicada, glicose, pressão arterial sistólica e pressão arterial diastólica no GI, após 6 meses de cirurgia. Houve melhora significativa nas variáveis relacionadas à QV, exceto nos aspectos emocionais. Conclui-se que a CB pode repercutir positivamente na maioria dos domínios da QV, na melhora do perfil bioquímico e na PA de pacientes obesos mórbidos após 3 e 6 meses de CB.

High-density lipoproteins estimated by an enzymatic cholesterol procedure, with a centrifugal analyzer.

1978 ◽  
Vol 24 (12) ◽  
pp. 2180-2184 ◽  
Author(s):  
K O Ash ◽  
W M Hentschel
Keyword(s):  
High Density Lipoprotein ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Sample Volume ◽  
High Density ◽  
High Density Lipoproteins ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Control Pool ◽  
Ambulatory Patients

Abstract We describe an assay for high-density lipoprotein cholesterol, adapted to a centrifugal analyzer, the GEMSAEC System 3, which includes use of an increased Mn2+concentration (91 mmol/liter) [J. Lipid Res. 19, 65 (1978)] and ethylenediaminetetraacetate [Clin. Chem. 22, 98 (1976)]. Modifications to the GEMSAEC system include reducing the mixing burst and preconditioning the sample tip. Accuracy of this procedure, as assessed by analysis of a control pool from the Center for Disease Control, was 99.2%. Day-to-day precision for two control pools was 320 +/- 13 and 506 +/- 17 mg/liter. Serum sample volume was decreased to 0.5 ml. In blanks with heparin/Mn2+ present, the pseudocholesterol concentrations resulting from a reaction of the enzymatic cholesterol reagent and the heparin/Mn2+ precipitating reagent depend on the source of the enzymatic reagent and appear to be enhanced slightly by the use of ethylenediaminetetraacetate. Pseudocholesterol concentrations reach a maximum at heparin/Mn2+ concentrations well below those needed to completely precipitate the low-density and very-low-density lipoprotein fractions. Population reference values were obtained from analyses done on 224 local physicians (mean: male, 500 mg/liter; female, 620 mg/liter) and 156 ambulatory patients (mean: male, 463 mg/liter; female, 553 mg/liter).

scholarly journals Low density lipoprotein and very low density lipoprotein are selectively bound by aggregated C-reactive protein.

1982 ◽  
Vol 156 (1) ◽  
pp. 230-242 ◽  
Author(s):  
F C de Beer ◽  
A K Soutar ◽  
M L Baltz ◽  
I M Trayner ◽  
A Feinstein ◽  
...  
Keyword(s):  
Acute Phase ◽  
Solid Phase ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
C Reactive Protein ◽  
Calcium Dependent ◽  
Reactive Protein

C-reactive protein (CRP), the classical acute-phase protein, can bind phospholipids by virtue of its specific, calcium-dependent reactivity with phosphorylcholine residues. However, analysis of acute-phase serum by gel filtration and by density gradient ultracentrifugation showed that the CRP was in a free, uncomplexed form, despite the coexistent presence of the various classes of serum lipoproteins, all of which contain phospholipids. In contrast, when isolated CRP was aggregated by immobilization at a sufficient density on a solid phase and then exposed to normal human serum, it selectively bound low density lipoprotein (LDL) and traces of very low density lipoprotein. The reaction was calcium dependent and reversible by free phosphorylcholine but not by heparin. LDL isolated from normal plasma was also bound by aggregated CRP. CRP reacts in vitro with a wide variety of different ligands both of extrinsic and of autogenous origin, e.g., microbial products and damaged cell membranes, respectively. If CRP aggregated in vivo by complexing with these ligands than acquires the capacity to selectively bind LDL, the phenomenon may have significant implications for the function of CRP and for the metabolism, clearance, and deposition of LDL.

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