Sviridov D D, Safonova I G, Nano J L, Pavlov M Y, Rampal P, Repin V S, Smirnov V N
Institute of Experimental Cardiology, Cardiology Research Center, Moscow, Russia.
J Lipid Res. 1993 Feb;34(2):331-9.
A new model to study cholesterol uptake in the human intestine in vitro is described. Human small intestine organ cultures were incubated with mixed micelles containing bile acid, phospholipid, and cholesterol or its nonabsorbable analogue, sitosterol; trace amounts of labeled cholesterol or sitosterol were added to the micelles. After incubation, the lipids were extracted from the cells and cholesterol and sitosterol uptake was evaluated. Specific cholesterol uptake was determined as a difference between cholesterol and sitosterol uptake. Cholesterol, but not sitosterol, uptake was time- and dose-dependent. Rapid and slow phases of cholesterol uptake were observed. Cholesterol uptake was also temperature-dependent. Removal of epithelial cells from human intestine explants reduced cholesterol, but not sitosterol, uptake. Inhibition of acyl CoA:cholesterol acyltransferase by Sandoz compound 58-035 and treatment with monensin reduced cholesterol uptake, but not sitosterol uptake, in a dose-dependent manner. In contrast, treatment of cultures with an inhibitor of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase, lovastatin, stimulated cholesterol, but not sitosterol, uptake in a dose-dependent manner; mevalonic acid reversed the effect of lovastatin. The presented model allows large-scale in vitro studies of different stages of cholesterol absorption in the human intestine.
本文描述了一种用于体外研究人体肠道胆固醇摄取的新模型。将人小肠器官培养物与含有胆汁酸、磷脂和胆固醇或其不可吸收类似物（植物甾醇）的混合微团一起孵育；向微团中添加痕量的标记胆固醇或植物甾醇。孵育后，从细胞中提取脂质并评估胆固醇和植物甾醇的摄取情况。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。胆固醇摄取呈时间和剂量依赖性，而植物甾醇摄取则不然。观察到胆固醇摄取存在快速和缓慢阶段。胆固醇摄取也依赖于温度。从人肠道外植体中去除上皮细胞可降低胆固醇摄取，但不影响植物甾醇摄取。山道士化合物58 - 035对酰基辅酶A：胆固醇酰基转移酶的抑制作用以及莫能菌素处理均以剂量依赖性方式降低胆固醇摄取，但不影响植物甾醇摄取。相反，用3 - 羟基 - 3 - 甲基戊二酰辅酶A还原酶抑制剂洛伐他汀处理培养物以剂量依赖性方式刺激胆固醇摄取，但不影响植物甾醇摄取；甲羟戊酸可逆转洛伐他汀的作用。所提出的模型允许对人体肠道胆固醇吸收的不同阶段进行大规模体外研究。
