[Effect of chylomicron remnants on cholesterol metabolism in cultured rabbit hepatocytes: production of very low density lipoproteins and bile acids].
Primary cultures of rabbit hepatocytes were used to investigate the effect of purified (B-100 free) chylomicron remnants (CR) on lipid and bile acid metabolism. ApoB-100-containing lipoproteins were removed from the CR-enriched plasma fraction by affinity column chromatography on Sepharose 4B conjugated with anti-apoB-100 monoclonal antibodies. CR were shown to stimulate the accumulation of neutral lipids in hepatocytes in a dose-response manner. After 24-hour preincubation of rabbit hepatocytes with 50 micrograms protein/ml CR the cellular neutral lipid content increased: 1.9-4-fold for triglycerides, 1.5-3.7-fold for free cholesterol and 1.5-2.5-fold for esterified cholesterol. This accumulation was accompanied by a decreasing incorporation of [14C] acetate into cholesterol (80-90%) and triglycerides (70-80%). At the same time the incorporation of [14]oleate into triglycerides increased by 50-65%. The inhibited biosynthesis of fatty acids might account for this effect. No effect of CR on cholesterol esterification by [14C]oleate was observed. CR increased the amount of triglycerides and free cholesterol secreted in very low density lipoproteins (VLDL). The secretion of taurocholic acid was decreased. These data confirm our hypothesis that dietary cholesterol is preferentially secreted by hepatocytes within VLDL but is not accumulated as cholesterol esters or oxidized to bile acids.
Novikov
D K
DK
Kosykh
V A
VA
Trakht
I N
IN
Podrez
E A
EA
Repin
V S
VS
D000818:Animals; D001647:Bile Acids and Salts / Q000096:biosynthesis*; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism*; D002914:Chylomicrons / Q000502:physiology*; D004951:Esterification; D008079:Lipoproteins, VLDL / Q000096:biosynthesis*; D008099:Liver / Q000378:metabolism*; D011817:Rabbits; D013656:Taurocholic Acid / Q000378:metabolism; D014280:Triglycerides / Q000096:biosynthesis
D001647:Bile Acids and Salts; D002914:Chylomicrons; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D013656:Taurocholic Acid; D002784:Cholesterol
Vliianie remnantov khilomikron na metabolizm kholesterina v kul'tiviruemykh gepatotsitakh krolika: produktsiia lipoproteidov ochen' nizkoĭ plotnosti i zhelchnykh kislot.