[A procedure for determining the oxidative modification of apolipoproteins in low-density lipoproteins].
The purpose of the present study was to develop a new procedure for estimating the oxidative modification of apolipoproteins in low-density lipoproteins (LDLs). The procedure was developed to use blood serum from 153 males aged 45-65 years, including 69 patients with coronary angiography-verified coronary atherosclerosis and 84 males from a representative sample from Novosibirsk residents of the same age. The new procedure is as follows: a rapid method for isolating serum LDLs, their apolipoprotein (apoLP) protein measurement by the Lowry procedure, their precipitation, a reaction with 2,4-dinitrophenylhydrazine in 2 M HCl solution, by subsequently rinsing in the ethanol:ethyl acetate (1:1) solution, dissolving the precipitate in 8 M urea, and by determining the level of the resultant dinitrophenylhydrazones by spectrophotometry at 363 nm, followed by conversion to LDL concentration of apoLP. The procedure is of informative value for the degree of oxidative LDL modification of apoLP under oxidative stress; it is technically simple, takes little time, and shows a good reproducibility. The values of determined oxidized LDL apoLP by the developed procedure highly positively correlated with the estimates of an oxidized total blood protein fraction and with the values of endothelial dysfunction and did not with the parameters of blood LDL peroxidation. The detected elevated oxidation LDL apoLP in males with coronary atherosclerosis suggests that this index is an additional marker of potentially atherogenic LDL changes.
Iu I
IuI
Ragino
Ia V
IaV
Polonskaia
E V
EV
Sadovskiĭ
D000368:Aged; D001053:Apolipoproteins / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood*; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D011499:Protein Processing, Post-Translational; D015203:Reproducibility of Results; D012800:Siberia; D013056:Spectrophotometry, Ultraviolet
D001053:Apolipoproteins; D015415:Biomarkers; D008077:Lipoproteins, LDL