Safonova I G, Sviridov D D, Nano J L, Rampal P, Repin V S
Institute of Experimental Cardiology, Cardiology Research Center, Moscow, Russia.
Biochim Biophys Acta. 1994 Jan 3;1210(2):181-6. doi: 10.1016/0005-2760(94)90119-8.
A new model to study cholesterol absorption in the rat intestinal cells is described. Rat intestine epithelial cells IRD98 were incubated with mixed micelles containing bile acid, phospholipid, cholesterol or its nonabsorbable analogue, sitosterol, and trace amounts of [3H]cholesterol or [14C]sitosterol. Cholesterol and sitosterol uptake was then determined following lipid extraction; specific cholesterol uptake was determined as the difference between cholesterol and sitosterol uptake. Cholesterol, but not sitosterol, uptake was time- and dose-dependent and saturable. Loading of cells with non-lipoprotein cholesterol reduced cholesterol, but not sitosterol, uptake in a dose-dependent manner. In contrast, treatment of cells with an inhibitor of cholesterol synthesis, lovastatin, stimulated cholesterol, but not sitosterol, uptake in a dose-dependent manner. Treatment of cells with palmitic, caproic and oleic acids up-regulated specific cholesterol uptake, while linoleic and stearic acids had an opposite effect. None of the fatty acids affected sitosterol uptake.
本文描述了一种用于研究大鼠肠道细胞中胆固醇吸收的新模型。将大鼠肠上皮细胞IRD98与含有胆汁酸、磷脂、胆固醇或其不可吸收类似物（植物甾醇）以及微量[3H]胆固醇或[14C]植物甾醇的混合微团一起孵育。脂质提取后测定胆固醇和植物甾醇的摄取量；特定胆固醇摄取量通过胆固醇摄取量与植物甾醇摄取量之差来确定。胆固醇摄取具有时间和剂量依赖性且可饱和，而植物甾醇摄取则不然。用非脂蛋白胆固醇加载细胞以剂量依赖性方式降低胆固醇摄取，但不降低植物甾醇摄取。相反，用胆固醇合成抑制剂洛伐他汀处理细胞以剂量依赖性方式刺激胆固醇摄取，但不刺激植物甾醇摄取。用棕榈酸、己酸和油酸处理细胞可上调特定胆固醇摄取，而亚油酸和硬脂酸则具有相反的作用。所有脂肪酸均不影响植物甾醇摄取。
