Guertin F, Brunet S, Gavino V, Tuchweber B, Levy E
Centre de recherche Hôpital Ste-Justine, Université de Montréal, Québec, Canada.
Biochem Biophys Res Commun. 1995 Jul 6;212(1):1-8. doi: 10.1006/bbrc.1995.1927.
In order to study in vivo the effect of modified high density lipoprotein (HDL) on the movement of free cholesterol to liver cells and bile, we injected i.v. into rats, native or malondialdehyde modified HDL labelled with [14C]cholesterol. Bile analysis indicated that the contribution of labelled cholesterol to bile acid secretion was diminished in the group receiving MDA-modified HDL when compared to control group. On the other hand, the liver analysis revealed higher radioactivity in the treated group. A separation of liver cells into parenchymal, endothelial, and kupffer at 90 min after the injection of MDA-modified HDL or native HDL indicated that the endothelial cell uptake of labelled free cholesterol from MDA-modified HDL was 2.6-fold higher than for native HDL. It is suggested that liver endothelial cells may be involved in the protection against atherogenoic oxidized lipoprotein. However, with regard to our finding, the uptake of cholesterol from modified HDL was detrimental to bile acid secretion.
为了在体内研究修饰的高密度脂蛋白（HDL）对游离胆固醇向肝细胞和胆汁转运的影响，我们经静脉向大鼠注射了用[14C]胆固醇标记的天然或丙二醛修饰的HDL。胆汁分析表明，与对照组相比，接受丙二醛修饰HDL的组中，标记胆固醇对胆汁酸分泌的贡献减少。另一方面，肝脏分析显示处理组的放射性更高。在注射丙二醛修饰HDL或天然HDL 90分钟后，将肝细胞分离为实质细胞、内皮细胞和枯否细胞，结果表明，内皮细胞从丙二醛修饰HDL摄取标记游离胆固醇的量比从天然HDL摄取的量高2.6倍。提示肝脏内皮细胞可能参与了对致动脉粥样硬化氧化脂蛋白的防御。然而，就我们的发现而言，从修饰HDL摄取胆固醇对胆汁酸分泌是有害的。
