Plasma carriers influence the uptake of cholecalciferol by human hepatoma-derived cells.
The uptake of [3H]cholecalciferol by the human hepatoma-derived cell lines Hep G2 and Hep 3B was examined as a function of the sterol's presentation on various plasma proteins at their native concentrations. Control cultures utilized devitalized cells cross-linked with glutaraldehyde and estimated nonspecific sterol adherence to cells. With both cell lines, neither albumin nor plasma vitamin D binding protein permitted cholecalciferol uptake above control values. With Hep G2 cells, only low-density lipoprotein presentation of the sterol resulted in significant cellular uptake that had features resembling a receptor-mediated process. With Hep 3B, only high-density lipoprotein presentation of the sterol resulted in a significant uptake that was cell, carrier, and time dependent. These results support the hypothesis that lipoprotein carriers could account for the efficient hepatic accumulation of cholecalciferol in vivo.
Haddad
J G
JG
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
Aden
D P
DP
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T C
TC
D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002352:Carrier Proteins / Q000097:blood*; D002762:Cholecalciferol / Q000378:metabolism*; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008113:Liver Neoplasms / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000378:metabolism
D002352:Carrier Proteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D002762:Cholecalciferol