Effect of labeling of plasma lipoproteins with [(3)H]cholesterol on values of esterification rate of cholesterol in apolipoprotein B-depleted plasma.
The fractional esterification rate of cholesterol in apolipoprotein B (apoB)-depleted plasma (FER(HDL)) is a good indicator of particle size distribution in high density lipoprotein (HDL) and low density lipoprotein (LDL). However, there has been a discrepancy in the absolute values of FER(HDL) published by different laboratories. Because the main difference between the methods was in the labeling of lipoproteins with [(3)H]cholesterol we investigated the effect of using Corning immunoplates and paper discs as carriers of the labeled unesterified cholesterol. We found that Corning plates trap some (3)H-labeled free cholesterol, which is released during incubation at 37 degrees C. This means that this additional (3)H-labeled free cholesterol is exposed to lecithin: cholesterol acyltransferase (LCAT) for a shorter time and artificially decreases FER(HDL). Using paper discs discarded before incubation as carriers of the (3)H-labeled free cholesterol results in complete labeling of HDL and thus yields higher values of FER(HDL).
Dobiásová
M
M
Institute of Physiology, Academy of Sciences of the Czech Republic, Prague 14220, Czech Republic.
Adler
L
L
Ohta
T
T
Frohlich
J
J
D001055:Apolipoproteins B / Q000097:blood / Q000172:deficiency*; D002784:Cholesterol / Q000097:blood*; D002788:Cholesterol Esters / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D004951:Esterification; D006801:Humans; D007700:Kinetics; D008074:Lipoproteins / Q000097:blood*; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000097:blood; D014316:Tritium
D001055:Apolipoproteins B; D002788:Cholesterol Esters; D008076:Cholesterol, HDL; D008074:Lipoproteins; D014316:Tritium; D002784:Cholesterol; D007862:Phosphatidylcholine-Sterol O-Acyltransferase