Use of the TLX ultracentrifuge for the isolation of different density lipoproteins and effects of freeze/thawing of human plasma before ultracentrifugation

2008 ◽  
Vol 46 (9) ◽  
Author(s):  
Valentine Charlton-Menys ◽  
Jelena Chobotova ◽  
Paul N. Durrington
Keyword(s):  
High Density Lipoprotein ◽  
High Density Lipoprotein Cholesterol ◽  
Apolipoprotein B ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Density ◽  
Low Density ◽  
Small Dense Ldl ◽  
Significant Difference ◽  
Fresh Plasma

Abstract: Isolation of different density lipoproteins by ultracentrifugation can require lengthy centrifugation times and freeze/thawing of plasma may influence recovery.: We isolated a range of lipoproteins using a preparative ultracentrifuge and the TLX micro-ultracentrifuge and determined the effect of freeze/thawing of plasma beforehand.: In fresh plasma, there was no significant difference in results for small-dense low-density lipoprotein apolipoprotein B (LDL apoB) (density >1.044 g/mL) or cholesterol at density >1.006 g/mL. Freeze/thawing had no effect on closely correlated results for small-dense LDL apoB (r=0.85; p<0.0001) or high-density lipoprotein (r=0.93; p<0.0001).: The TLX micro-ultracentrifuge is a reliable alternative to the preparative ultracentrifuge and freeze/thawing has only a small effect on small-dense LDL apoB or high-density lipoprotein cholesterol.Clin Chem Lab Med 2008;46:1285–8.

scholarly journals A Comparison of the Phosphotungstate Magnesium Precipitation and Heparin-Manganese Precipitation Procedures for Estimating High-Density Lipoprotein Cholesterol

1980 ◽  
Vol 17 (2) ◽  
pp. 105-108 ◽  
Author(s):  
GD Calvert ◽  
Rosemary A Yeates ◽  
Tuna Mannik
Keyword(s):  
High Density Lipoprotein ◽  
High Density Lipoprotein Cholesterol ◽  
Apolipoprotein B ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Final Concentration ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Cholesterol Measurement

The phosphotungstate-MgCl2 method for precipitating very low density and low density lipoproteins from plasma precipitates up to about 7 % of high density lipoprotein. The heparin-MnCl2 method, used at a final MnCl2 concentration of 0092 mol/l, does not seem to precipitate any high density lipoprotein but precipitates essentially all apolipoprotein B containing very low density and low density lipoprotein. When the final concentration of MnCl2 is 0046 mol/l, precipitation of apolipoprotein B containing very low density and low density lipoprotein is frequently incomplete. The herapin-MnCl2 method, when the MnCl2 final concentration is 0·092 mol/l, is the preferred method for high density lipoprotein cholesterol measurement if the cholesterol assay is unaffected by either heparin or MnCl2. High density lipoprotein cholesterol results, using this method, are higher than with the phosphotungstate MgCl2 method and lower than with the heparin MnCl2 method when the MnCl2 final concentration is 0·046 mol/l.

The Effects of Low-Density Lipoprotein and High-Density Lipoprotein on Blood Viscosity Correlate with their Association with Risk of Atherosclerosis in Humans

1997 ◽  
Vol 92 (5) ◽  
pp. 473-479 ◽  
Author(s):  
Gregory D. Sloop ◽  
David W. Garber
Keyword(s):  
High Density Lipoprotein ◽  
Total Cholesterol ◽  
High Density Lipoprotein Cholesterol ◽  
Blood Viscosity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol

1. Increased blood or plasma viscosity has been observed in almost all conditions associated with accelerated atherosclerosis. Cognizant of the enlarging body of evidence implicating increased viscosity in atherogenesis, we hypothesize that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity correlate with their association with risk of atherosclerosis. 2. Blood viscometry was performed on samples from 28 healthy, non-fasting adult volunteers using a capillary viscometer. Data were correlated with haematocrit, fibrinogen, serum viscosity, total cholesterol, high-density lipoprotein-cholesterol, triglycerides and calculated low-density lipoprotein-cholesterol. 3. Low-density lipoprotein-cholesterol was more strongly correlated with blood viscosity than was total cholesterol (r = 0.4149, P = 0.0281, compared with r = 0.2790, P = 0.1505). High-density lipoprotein-cholesterol levels were inversely associated with blood viscosity (r = −0.4018, P = 0.0341). 4. To confirm these effects, viscometry was performed on erythrocytes, suspended in saline, which had been incubated in plasma of various low-density lipoprotein/high-density lipoprotein ratios. Viscosity correlated directly with low-density lipoprotein/high-density lipoprotein ratio (n = 23, r = 0.8561, P < 0.01). 5. Low-density lipoprotein receptor occupancy data suggests that these effects on viscosity are mediated by erythrocyte aggregation. 6. These results demonstrate that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity in healthy subjects correlate with their association with risk of atherosclerosis. These effects on viscosity may play a role in atherogenesis by modulating the dwell or residence time of atherogenic particles in the vicinity of the endothelium.

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