期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1976
卷号:73
期号:10
页码:3680-3684
DOI:10.1073/pnas.73.10.3680
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The influence of lipoprotein composition on free cholesterol (RC) esterification and accumulation of esterified cholesterol (EC) was studied in cells of Fu5AH rat hepatoma exposed to culture media supplemented with (FC/P) ranging from 0.6 to 2.8. In the presence of normal human serum, FC-lecithin dispersions witb a FC/P greater than one stimulated both the esterification of FC and the accumulation of cellular EC. Conversely, dispersions with FC/P values of approximately one had no effect on either FC esterification or the accumulation of EC when compared to cells grown in the absence of lipid dispersions. No stimulation of cellular response was obtained when FC-rich dispersions were added to cells in the absence of serum; however, stimulation was observed when cells were exposed to isolated human serum lipoproteins (very low density, low density, and high density). With each lipoprotein, FC-lecithin dispersions with FC/P values less than one inhibited cholesteryl ester accumulation, FC-rich dispersions stimulated, and dispersions with FC/P values of approximately one had an effect equivalent to that of isolated lipproteins alone. These studies extablish that cellular FC esterification and EC content are not influenced solely by the FC concentration of medium, but rather respond to the ratio of FC to phospholipidl These studies also suggest that serum lipoproteins participate in the transfer of FC carried by FC-rich lecithin dispersions to cells.