High-density lipoprotein (HDL3)-associated α-tocopherol is taken up by HepG2 cells via the selective uptake pathway and resecreted with endogenously synthesized apo-lipoprotein B-rich lipoprotein particles

α-Tocopherol (αTocH) is transported in association with lipoproteins in the aqueous milieu of the plasma. Although up to 50% of circulating αTocH is transported by high-density lipoproteins (HDLs), little is known about the mechanisms of uptake of HDL-associated αTocH. During the current study, human apolipoprotein (apo)E-free HDL subclass 3 (HDL $ ) labelled with ["%C]αTocH was used to investigate uptake mechanisms of HDL $ -associated αTocH by a permanent hepatoblastoma cell line (HepG2). HDL $ -associated αTocH was taken up independently of HDL $ holoparticles in excess of apoA-I comparable with the non-endocytotic delivery of cholesteryl esters to cells termed the ‘selective ’ cholesteryl ester uptake pathway. Experiments with unlabelled HDL $ demonstrated net mass transfer of αTocH toHepG2 cells. Time-dependent studies with ["%C]αTocH-