Sviridov D D, Safonova I G, Gusev V A, Talalaev A G, Tsibulsky V P, Ivanov V O, Preobrazensky S N, Repin V S, Smirnov V N
Metabolism. 1986 Jul;35(7):588-95. doi: 10.1016/0026-0495(86)90162-9.
The interaction of high density lipoproteins (HDL) with isolated epithelial cells of human small intestine (enterocytes) was studied. 125I-HDL3 (density = 1,125 to 1,126 g/cm3) exhibit a high-affinity (Kd = 8.3 X 10(-8). Bmax = 886 ng/mg cell protein), saturable and reversible binding to isolated enterocytes. In the presence of excess unlabeled HDL3, the cell surface-bound 125I-HDL3 are released into the medium nondegraded. Treatment of cells with pronase does not affect 125I-HDL3 binding. The binding is accompanied with internalization and degradation of 125I-HDL3. Chloroquine inhibits the degradation and increases 125I-HDL3 uptake. A threefold excess of HDL3 and HDL2 inhibits the binding and degradation of 125I-HDL3 by 60%, whereas a 20-fold excess of low density lipoproteins (LDL), only by 20%. HDL3 (20 to 1,000 micrograms/mL) stimulates the synthesis of sterols and inhibits sterol ester synthesis in enterocytes. The obtained results make it possible to assume that epithelial cells of the small intestine may participate in the catabolism of HDL in human organism.
研究了高密度脂蛋白（HDL）与分离的人小肠上皮细胞（肠细胞）之间的相互作用。125I-HDL3（密度=1.125至1.126 g/cm3）对分离的肠细胞表现出高亲和力（Kd = 8.3×10（-8），Bmax = 886 ng/mg细胞蛋白）、可饱和且可逆的结合。在过量未标记的HDL3存在下，细胞表面结合的125I-HDL3未降解地释放到培养基中。用链霉蛋白酶处理细胞不影响125I-HDL3的结合。这种结合伴随着125I-HDL3的内化和降解。氯喹抑制降解并增加125I-HDL3的摄取。三倍过量的HDL3和HDL2抑制125I-HDL3的结合和降解达60%，而二十倍过量的低密度脂蛋白（LDL）仅抑制20%。HDL3（20至1000微克/毫升）刺激肠细胞中固醇的合成并抑制固醇酯的合成。所得结果使得可以推测小肠上皮细胞可能参与人体中HDL的分解代谢。
