Hepatic uptake and metabolism of free cholesterol from different lipoprotein classes. An in vivo study in the rat.
Hepatic metabolism of [14C]cholesterol, vehiculated by LDL, HDL2 and HDL3 lipoprotein particles, has been studied in rats with a permanent biliary drainage. The lipoprotein fractions were infused individually by a jugular vein catheter and bile was collected for 180 min after the administration. At the end of this period, the animals were killed and the blood and livers were collected. The free cholesterol of the HDL2 fraction was secreted into bile, mainly as bile salt, preferentially to that associated with HDL3 and LDL fractions (11.7% vs. 2.3% and 0.3%, respectively). The free cholesterol of the HDL3 fraction, on the other hand, was taken up by liver more quickly and in a higher proportion than that associated with other lipoprotein fractions. The label incorporation in this lipoprotein fraction was secreted earlier and not transformed into bile. The contribution of LDL-vehiculated free cholesterol to bile secretion was small and the hepatic uptake amounted to no more than 12% of the injected label.
Bravo
E
E
Istituto Superiore di Sanita', Laboratory of Metabolism and Pathological Biochemistry, Rome, Italy.
Cantafora
A
A
Argiolas
L
L
D000818:Animals; D001646:Bile / Q000378:metabolism; D001692:Biological Transport; D002788:Cholesterol Esters / Q000378:metabolism; D008076:Cholesterol, HDL / Q000378:metabolism* / Q000493:pharmacokinetics; D008078:Cholesterol, LDL / Q000378:metabolism* / Q000493:pharmacokinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D002788:Cholesterol Esters; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL