RECOGNITION SITES ON RAT-LIVER CELLS FOR OXIDATIVELY MODIFIED BETA-VERY LOW-DENSITY LIPOPROTEINS
RECOGNITION SITES ON RAT-LIVER CELLS FOR OXIDATIVELY MODIFIED BETA-VERY LOW-DENSITY LIPOPROTEINS
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DOI：
10.1161/01.atv.12.1.41
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发表时间：
1992-01-01
期刊：
影响因子：
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通讯作者：
VANBERKEL, TJC
中科院分区：
文献类型：
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作者：
DERIJKE, YB;HESSELS, EMAJ;VANBERKEL, TJC
The in vivo fate of beta-very low density lipoproteins (beta-VLDLs) was investigated after Cu2+-mediated oxidative modification (Ox-beta-VLDL). Ox-beta-VLDL may be physiologically relevant under conditions of defective VLDL removal by the liver (type III hyperlipoproteinemia) or overloading of the remnant receptor (high cholesterol feeding). On oxidation of beta-VLDL, the kinetics of its removal from the blood and uptake by the liver are unchanged. However, in contrast to beta-VLDL, which is recognized by the remnant receptor of parenchymal cells, liver uptake of Ox-beta-VLDL is mediated mainly by Kupffer cells (65% of liver-associated radioactivity). In vitro competition studies show that the cell association and degradation of iodine-125-labeled Ox-beta-VLDL by both liver endothelial and Kupffer cells are only marginally competed for by acetylated LDL (10-20%), while an efficient blockade is noted with Ox-beta-VLDL, oxidized low density lipoproteins, or polyinosinic acid (80-90%). The capacity of Kupffer cells to associate with and degrade I-125-Ox-beta-VLDL appears to be twofold higher than for endothelial cells. It is concluded that on oxidation of beta-VLDL, the recognition system responsible for the uptake of beta-VLDL from the blood circulation is shifted from the remnant receptor to a specific oxidized-lipoprotein receptor. The efficiency of the scavenger activity on Kupffer cells will then form the protection system against the prolonged circulation of these atherogenic lipoproteins in the blood.
