Arbogast L Y, Rothblat G H, Leslie M H, Cooper R A
Proc Natl Acad Sci U S A. 1976 Oct;73(10):3680-4. doi: 10.1073/pnas.73.10.3680.
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.
在暴露于补充有（游离胆固醇/磷脂）（FC/P）范围为0.6至2.8的培养基中的Fu5AH大鼠肝癌细胞中，研究了脂蛋白组成对游离胆固醇（FC）酯化和酯化胆固醇（EC）积累的影响。在正常人血清存在的情况下，FC/P大于1的FC-卵磷脂分散体刺激了FC的酯化和细胞内EC的积累。相反，与在无脂质分散体的情况下生长的细胞相比，FC/P值约为1的分散体对FC酯化或EC积累均无影响。在无血清的情况下向细胞中添加富含FC的分散体时，未观察到细胞反应的刺激；然而，当细胞暴露于分离的人血清脂蛋白（极低密度、低密度和高密度）时，观察到了刺激。对于每种脂蛋白，FC/P值小于1的FC-卵磷脂分散体抑制胆固醇酯积累，富含FC的分散体刺激，而FC/P值约为1的分散体的作用与单独的分离脂蛋白相当。这些研究表明，细胞内FC酯化和EC含量不仅受培养基中FC浓度的影响，还对FC与磷脂的比例有反应。这些研究还表明，血清脂蛋白参与了富含FC的卵磷脂分散体携带的FC向细胞的转移。
