Mathai D, Fidge N, Tozuka M, Mitchell A
Baker Medical Research Institute, Melbourne, Victoria, Australia.
Arteriosclerosis. 1990 Nov-Dec;10(6):1045-50. doi: 10.1161/01.atv.10.6.1045.
We investigated the regulation of putative high density lipoprotein (HDL) receptors in rat liver after cholesterol feeding and the administration of cholesterol-lowering drugs to rats. The expression of two plasma membrane HDL binding proteins (HB1 and HB2) were compared in control and treated livers by first separating membrane proteins on sodium dodecyl sulfate-polyacrylamide gels and quantitating HB1 and HB2 levels with a specific ligand blot assay. Of the various treatments used, only simvastatin or simvastatin plus cholestyramine produced significant changes, with reductions of up to 40% and 60%, respectively, for HB1 and HB2. The effect on the binding proteins was not associated with changes in serum cholesterol concentrations, which did not change significantly after either treatment, although a marked rise in liver cholesterol concentration after cholesterol was associated with a moderate increase in HB2 expression. We show evidence for regulation of the levels of hepatic HDL binding proteins and provide another important criterion for the acceptance of HB1 and HB2 as components of a functional HDL receptor.
我们研究了给大鼠喂食胆固醇并给予降胆固醇药物后，大鼠肝脏中假定的高密度脂蛋白（HDL）受体的调节情况。通过首先在十二烷基硫酸钠 - 聚丙烯酰胺凝胶上分离膜蛋白，并用特异性配体印迹分析法对HB1和HB2水平进行定量，比较了对照肝脏和处理后肝脏中两种质膜HDL结合蛋白（HB1和HB2）的表达。在所使用的各种处理中，只有辛伐他汀或辛伐他汀加考来烯胺产生了显著变化，HB1和HB2分别降低了高达40%和60%。对结合蛋白的影响与血清胆固醇浓度的变化无关，两种处理后血清胆固醇浓度均未显著改变，尽管喂食胆固醇后肝脏胆固醇浓度显著升高与HB2表达适度增加有关。我们展示了肝脏HDL结合蛋白水平受调节的证据，并为将HB1和HB2接受为功能性HDL受体的组成部分提供了另一个重要标准。
