Lipoprotein-mediated efflux of radiolabeled cholesterol from cells does not indicate net removal of cellular cholesterol mass

1989 ◽  
Vol 67 (10) ◽  
pp. 719-723 ◽  
Author(s):  
Subramanian Ranganathan ◽  
John D. Gasman ◽  
Hideo Matsuura ◽  
Bruce A. Kottke
Keyword(s):  
Cultured Cells ◽  
Density Lipoprotein ◽  
Cholesterol Content ◽  
Low Density Lipoproteins ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Mass Measurements ◽  
Cholesterol Removal ◽  
Cellular Cholesterol

The efflux of cholesterol from human skin fibroblasts was determined using radioisotope techniques and mass measurements. When the cells were labeled with [14C]- or [3H]-cholesterol and then incubated with very low density, low density, or high density lipoproteins or with serum, 20 to 30% of the label was released into the medium in 20 h. However, when the cellular cholesterol content was determined after incubation with various lipoproteins under identical conditions, only the heavier subfraction of high density lipoproteins (HDL3) caused a significant decrease in cellular cholesterol. This net removal of cholesterol can be observed in the cells without overloading them with cholesterol, by incubation with low density lipoproteins. Time studies indicated that at least 24 h of incubation is required to detect significant removal of cellular cholesterol. These experiments show that methods using the release of labeled cholesterol from cultured cells to determine net cholesterol removal mediated by high density lipoprotein, although currently used by many investigators, can lead to erroneous conclusions when employed without the measurement of cholesterol mass.Key words: low-density lipoproteins, high-density lipoproteins, fibroblasts, cholesterol, bidirectional flux.

Evaluation of the Polyethylene Glycol Precipitation Method for the Estimation of High-Density Lipoprotein Cholesterol

1981 ◽  
Vol 18 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Catherine J Briggs ◽  
Deborah Anderson ◽  
P Johnson ◽  
T Deegan
Keyword(s):  
Polyethylene Glycol ◽  
High Density Lipoprotein ◽  
High Density Lipoprotein Cholesterol ◽  
Density Lipoprotein ◽  
Low Density Lipoproteins ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Selective Precipitation

Treatment of fresh sera with polyethylene glycol 6000 at a final concentration of 100 g/l produced selective precipitation of low-density lipoproteins with only traces of contamination with high-density lipoproteins, as determined by electroimmunoassay using antisera to human α1-lipoprotein and human β-lipoprotein. Supernatants collected for high-density lipoprotein-cholesterol estimation were free from low-density lipoproteins. Precipitates sedimented readily from specimens with high triglyceride contents, and secondary precipitation during enzymatic cholesterol determinations was absent. Values obtained by this method correlated well with those obtained by precipitation of low-density lipoproteins with heparin and manganous ions at concentrations optimal for discrete separation of lipoprotein classes (r = 0·975; P<0·001).

The therapeutic effect of some drugs and vegetable juices on the lipid profiles in male rabbits induced atherosclerosis.

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Sawsan Taha Ahmed al-Haddad ◽  
Zaid Mohammed Mubarak Almahdawi ◽  
Munife S. Ahmed Al-janabi
Keyword(s):  
Green Tea ◽  
Density Lipoprotein ◽  
Lemon Juice ◽  
Low Density Lipoproteins ◽  
High Density ◽  
High Density Lipoproteins ◽  
Control Group ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Group 5

This study was designed to test the therapeutic efficacy of some hypotensive drugs and vegetable drinks on some biochemical indicators in male rabbits, where atherosclerosis was developed using 1% cholesterol with food. This study was conducted in June until the end of July 2017 in the Pharmacology Department/ General Company for Pharmaceutical Industry in Samarra. In the study, 50 local rabbits were randomly distributed by 10 groups each containing 5 animals. The first group considered as the control group. The second group is the control group treated with 1% cholesterol with the food, the third group treated with cholesterol (1% and captopril 0.71 mg), group 4 (cholesterol 1% with atenolol 0.71 mg / kg), group 5 (cholesterol 1%, amlodipine 0.07 mg / kg) , group 6 treated with cholesterol 1% and aldomet (0.57 mg / kg), group 7 (cholesterol 1% and furosemide at 3.5 mg / kg), group 8 (cholesterol 1% with garlic syrup 2 ml), group 9 treatment cholesterol 1% and lemon juice), and group 10 Treatment with (1% cholesterol and green tea syrup 2 ml). The results of the study showed a significant increase (P≤0.01)) at the level of each of cholesterol triple and triglycerides, proteins and low density lipoproteins, very low density lipoproteins, also led to obtain a significant decrease in the level of high-density lipoproteins (HDL) in the treatment group with cholesterol 1% compared to control group. At the time of the treatment of anti- pressure drugs: Captopril, Atenolol, Amlodipine ,Aldomet, and Furosmide , there were no significant differences in the cholesterol level of all pharmacological groups. Moral differences were not found in LDL-C and there was a significant decrease (P≤0.01) of the level of triglycerides, proteins and very low density lipoproteins, and there was a significant increase in the level of high-density lipoproteins HDL-C, while treatment with plant juices, there was a significant decrease (P≤0.01) in the level of total cholesterol and triglycerides and LDL, and VLDL, high-density lipoprotein (HDL-C) increased when treated with garlic, lemon and green tea. We conclude pressure drugs of any kind can cure atherosclerosis or prevent high fat, unlike its counterparts OF plants, which have shown a significant effect on controlling lipid profile and reducing their effects and future risks on the heart.

scholarly journals Phospholipid transfer protein activity in two cholestatic patients

2004 ◽  
Vol 122 (4) ◽  
pp. 175-177 ◽  
Author(s):  
Eliana Cotta de Faria ◽  
Adriana Celeste Gebrin ◽  
Wilson Nadruz Júnior ◽  
Lucia Nassi Castilho
Keyword(s):  
Density Lipoprotein ◽  
Plasma Phospholipid ◽  
Low Density Lipoproteins ◽  
High Density ◽  
High Density Lipoproteins ◽  
Phospholipid Transfer Protein ◽  
Low Density ◽  
Protein Activity ◽  
Transfer Protein ◽  
Phospholipid Transfer

CONTEXT: Plasma phospholipid transfer protein mediates the transfer of phospholipids from triglyceride-rich lipoproteins, very low density lipoproteins and low density lipoproteins to high density lipoproteins, a process that is also efficient between high density lipoprotein particles. It promotes a net movement of phospholipids, thereby generating small lipid-poor apolipoprotein AI that contains particles and subfractions that are good acceptors for cell cholesterol efflux. CASE REPORT: We measured the activity of plasma phospholipid transfer protein in two cholestatic patients, assuming that changes in activity would occur in serum that was positive for lipoprotein X. Both patients presented severe hypercholesterolemia, high levels of low density lipoprotein cholesterol and, in one case, low levels of high density lipoprotein cholesterol and high levels of phospholipid serum. The phospholipid transfer activity was close to the lower limit of the reference interval. To our knowledge, this is the first time such results have been presented. We propose that phospholipid transfer protein activity becomes reduced under cholestasis conditions because of changes in the chemical composition of high density lipoproteins, such as an increase in phospholipids content. Also, lipoprotein X, which is rich in phospholipids, could compete with high density lipoproteins as a substrate for phospholipid transfer protein.

Composition of serum very-low-density and high-density lipoproteins in diabetes.

1980 ◽  
Vol 26 (9) ◽  
pp. 1261-1265 ◽  
Author(s):  
J Gabor ◽  
M Spain ◽  
N Kalant
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Cholesterol Content ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Protein Ratio ◽  
Apolipoprotein Ciii ◽  
Apoprotein Composition

Abstract We examined the cholesterol/protein ratio and the apoprotein composition of serum lipoproteins in a randomly selected population of maturity-onset diabetics and in a group of nondiabetics of similar age. We found no differences in cholesterol distribution between the groups as a whole, but diabetics with above-normal low-density lipoproteins (LDL) had decreased concentrations of high-density lipoprotein (HDL) cholesterol. In the diabetics as a whole, there was an increase in the cholesterol/protein ratio in HDL, a negative correlation between the amounts of LDL cholesterol and HDL cholesterol, an increase in the proportion of apolipoprotein C in very-low-density lipoprotein (VLDL), and a decrease in the proportion of the apolipoprotein AI component of HDL. In diabetic subjects with increased VLDL, there was an increase in the relative amount of apolipoprotein CIII, and a consequent decrease in the ratio of apolipoprotein CII/apolipoprotein CIII in the VLDL. In both diabetic and control subjects, apolipoprotein E and cholesterol content of VLDL were linearly related.

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.

Cholesterol determination in high-density lipoproteins separated by three different methods.

1977 ◽  
Vol 23 (5) ◽  
pp. 882-884 ◽  
Author(s):  
M F Lopes-Virella ◽  
P Stone ◽  
S Ellis ◽  
J A Colwell
Keyword(s):  
Clinical Laboratory ◽  
Density Lipoprotein ◽  
Low Density Lipoproteins ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Precipitation Technique ◽  
Simplified Method ◽  
Routine Clinical Laboratory ◽  
Cholesterol Determination

Abstract We describe a simplified method for measuring high-density lipoprotein cholesterol in serum after very-low- and low-density lipoproteins have been precipitated from the specimen with sodium phosphotungstate and Mg2+. Values so obtained correlate well with values obtained with the heparin-Mn2+ precipitation technique (r = 0.95, CV less than 5% in 66% of the subjects studied and between 5 and 10% in the remaining ones) or by ultracentrifugal separation (r = 0.82, CV less than 5% in 80% of the subjects studied and between 5 and 10% in the remaining ones). Our precipitation technique is more appropriate for routine clinical laboratory use.

Heparin--Mn2+ quantitation of high-density-lipoprotein cholesterol: an ultrafiltration procedure for lipemic samples.

1978 ◽  
Vol 24 (6) ◽  
pp. 900-904 ◽  
Author(s):  
G R Warnick ◽  
J J Albers
Keyword(s):  
High Density Lipoprotein ◽  
High Density Lipoprotein Cholesterol ◽  
Density Lipoprotein ◽  
Low Density Lipoproteins ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Low Speed ◽  
Twofold Increase

Abstract We describe a modified heparin--Mn2+ procedure for high-density-lipoprotein cholesterol quantitation, especially in lipemic samples. High-density-lipoproteins may be estimated as cholesterol remaining in plasma supernates after precipitation of other lipoproteins by heparin and Mn2+ treatment. However, in lipemic samples or those from non-fasting individuals, the lower density of the precipitated chylomicrons, very-low-, and low-density-lipoproteins frequently prevents their sedimentation by the usual low-speed centrifugation, and high-density-lipoprotein cholesterol thus is overestimated in the resulting turbid supernates. Sedimentation is improved by a twofold increase in Mn2+ concentration to 92 mmol/liter. The procedure reported here produced clear supernates in more than 95% of samples tested. Any remaining turbid supernates can be cleared by a simple, convenient ultrafiltration technique. The filtration removed essentially all of the very-low- and low-density-lipoproteins without removing appreciable amounts of high-density-lipoproteins.

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