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

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).

2021 ◽  
Vol 34 (1) ◽  
pp. 139-146
Author(s):  
Elham K. Nasser ◽  
Kithar R. Majeed ◽  
Hayder I. Ali

Fortified milk containing Lactobacillus plantarum, L. casei, and L. acidophilus isolates and their mixture were used in dosing the male albino rats at an age of 9-12 weeks at an average of 23 g with induced hypothyroidism at a concentration of 0.6 g.kg-1 of carbimazole. Total cholesterol, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL) were estimated. The results showed a significant increase in the level of triglycerides (TG), cholesterol and triglycerides. Low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL), with a significant decrease in the level of high-density lipoprotein (HDL) in infected male mice, compared to the control sample, and upon dosing with liquid milk fortified, it returned to its normal level without significant differences from the control group.


1987 ◽  
Vol 65 (3) ◽  
pp. 252-260 ◽  
Author(s):  
S. P. Tam ◽  
W. C. Breckenridge

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.


1977 ◽  
Vol 23 (7) ◽  
pp. 1238-1244 ◽  
Author(s):  
P N Demacker ◽  
H E Vos-Janssen ◽  
A P Jansen ◽  
A van 't Laar

Abstract We evaluated the dual-precipitation method for quantitative measurement of lipoproteins as described by Wilson and Spiger [J. Lab. Clin. Med. 82, 473 (1973)] for normo- and hyperlipemic sera, by comparison with the results obtained with ultracentrifugation. If serum with an above-normal triglyceride concentration is analyzed, the very-low-density lipoprotein cholesterol value obtained with the precipitation method is usually too low. For measurement of high-density lipoprotein cholesterol the ultracentrifugation and precipitation procedures give comparable results, but the latter method is preferred because sinking pre-beta-lipoproteins present in the high-density lipoprotein fraction isolated by means of the ultracentrifuge may result in falsely high values for cholesterol in that fraction. Therefore, at least for the determination of very-low-density lipoprotein cholesterol in hyperlipemic serum, the use of an ultracentrifuge remains necessary. Because few laboratories have an ultracentrifuge at their disposal, it seemed important to look at the stability of sera in view of the forwarding of samples. Also, a way of increasing the efficiency of the ultracentrifuge was studied. Sera can be stored for a week at 4 degrees C or for 54 h at room temperature without noticeable effect on lipoprotein values. Moreover, reliable values can be obtained with an ultracentrifugation time of 8 h (0.8 X 10(8) g-min).


2019 ◽  
Vol 15 (4) ◽  
pp. 401-407 ◽  
Author(s):  
Apoorva Bhushan ◽  
Mayank Kulshreshtha

Background: Agaricus bisporus (A. bisporus) is an edible basidiomycete mushroom native to grasslands in Europe and North America. A. bisporus, commonly known as white button mushroom (WBM), is widely cultivated in most countries, and it constitutes the bulk of all mushrooms consumed in the United States and Australia. Traditionally this fungus has used in the treatment of heart diseases. Also it has anti-ageing property.Mushrooms have been found effective against cancer, cholesterol reduction, stress, insomnia, asthma, allergies and diabetes. Objective: The present research was designed to appraise the cardioprotective activity of a hydroalcoholic extract of Agaricus bisporus (EEAB) on Isoproterenol (ISO) induced myocardial infarction (MI) in Albino Wistar rat. Traditionally, Agaricus bisporus is reported in the treatment of heart diseases, cancer, cerebral stroke and anti-ageing property. Materials and Methods: Wistar rats of different sex were randomly split into five groups namely positive control, negative control, standard, test-1 and test-2 and received distilled water, ISO (85 mg/kg), Simvastatin (10 mg/kg/day, oral) and EEAB (200 and 400 mg/kg/day, p.o.) for 30 days, respectively. MI was induced in rats by ISO at an interval of 24 hrs on 31 and 32 day and on the next day, blood was amassed through retro-orbital plexus for the assessment of biochemical markers (cholesterol, lowdensity lipoprotein, high-density lipoprotein, very low-density lipoprotein, triglycerides, alanine aminotransferase and total protein) and finally, the rats were immolated by cervical dislocation. The heart tissue was reaped instantly, cleaned with chilled isotonic saline and clasped in 10% buffered formalin and used for the histopathological analysis. Results: ISO p.o. administration significantly elevated the cholesterol, low density lipoprotein, very low density lipoprotein, triglycerides, alanine aminotransferase and aspartate aminotransferase levels while it decreases high-density lipoprotein and total protein in plasma and administration of EEAB decreases the level of cholesterol, low-density lipoprotein, very low-density lipoprotein, triglycerides, alanine aminotransferase and aspartate aminotransferase levels while it increases high-density lipoprotein and total protein levels. Pretreatment with EEAB protected the cardiotoxicity induced by ISO. The histopathological findings support the analysis of biochemical parameters, ISO-induced myocardium showed infracted zone with edema, inflammatory cells, lipid droplets, myocardial necrosis and vacuolization of myofibrils which were reduced. Conclusion: It can be an outcome that EEAB possessed cardioprotective activity against experimental and clinical studies of ISO-induced myocardial infarction in rats.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Azusa Yamazaki ◽  
Ryunosuke Ohkawa ◽  
Yuka Yamagata ◽  
Yuna Horiuchi ◽  
Shao-Jui Lai ◽  
...  

AbstractTriglyceride hydrolysis by lipoprotein lipase (LPL), regulated by apolipoproteins C-II (apoC-II) and C-III (apoC-III), is essential for maintaining normal lipid homeostasis. During triglyceride lipolysis, the apoCs are known to be transferred from very low-density lipoprotein (VLDL) to high-density lipoprotein (HDL), but the detailed mechanisms of this transfer remain unclear. In this study, we investigated the extent of the apoC transfers and their distribution in HDL subfractions, HDL2 and HDL3. Each HDL subfraction was incubated with VLDL or biotin-labeled VLDL, and apolipoproteins and lipids in the re-isolated HDL were quantified using western blotting and high-performance liquid chromatography (HPLC). In consequence, incubation with VLDL showed the increase of net amount of apoC-II and apoC-III in the HDL. HPLC analysis revealed that the biotin-labeled apolipoproteins, including apoCs and apolipoprotein E, were preferably transferred to the larger HDL3. No effect of cholesteryl ester transfer protein inhibitor on the apoC transfers was observed. Quantification of apoCs levels in HDL2 and HDL3 from healthy subjects (n = 8) showed large individual differences between apoC-II and apoC-III levels. These results suggest that both apoC-II and apoC-III transfer disproportionately from VLDL to HDL2 and the larger HDL3, and these transfers might be involved in individual triglyceride metabolism.


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