Role of the liver in low-density-lipoprotein catabolism in the rat.
Plasma low-density-lipoprotein (LDL) kinetics and hepatic LDL uptake were studied in the rat after an intravenous pulse injection of [14C]sucrose-labelled LDL. Some 96% of injected radioactivity was associated with apoprotein B of LDL (d 1.020-1.050). The disappearance of labelled LDL from plasma was accompanied by a linear increase in the hepatic uptake of LDL, up to 12 h after injection. Oestradiol treatment lowered plasma cholesterol concentration by 58% and the intravascular pool of LDL by 78%. This was associated with a 4-fold increase in the fractional catabolic rate of LDL and a 2-fold increase in the hepatic uptake of LDL. Oestradiol treatment did not significantly change the synthesis rate of LDL; it decreased the skin and lung uptake of LDL, but increased adrenal uptake. These results suggest that the liver plays an important role in the regulation of plasma LDL concentration.
D000818:Animals; D002850:Chromatography, Gel; D004958:Estradiol / Q000494:pharmacology; D007700:Kinetics; D008077:Lipoproteins, LDL / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013395:Sucrose / Q000378:metabolism; D014018:Tissue Distribution
C035247:LDL-sucrose; D008077:Lipoproteins, LDL; D004958:Estradiol; D013395:Sucrose