Carotenoid uptake and secretion by CaCo-2 cells:: β-carotene isomer selectivity and carotenoid interactions
Carotenoid uptake and secretion by CaCo-2 cells:: β-carotene isomer selectivity and carotenoid interactions
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DOI：
10.1194/jlr.m200068-jlr200
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发表时间：
2002-07-01
影响因子：
6.5
通讯作者：
Harrison, EH
中科院分区：
文献类型：
--
作者：
During, A;Hussain, MM;Harrison, EH
在油酸盐和牛磺酸胆酸盐存在的情况下，膜上分化的CaCo-2细胞单层能够聚集并分泌乳糜微粒。在这些条件下，细胞摄取和分泌β -胡萝卜素（β -c）到乳糜微粒的过程是曲线的、时间依赖的（2-16小时）、饱和的和浓度依赖的（7-10 muM的表观K-m）过程。在线性浓度条件下，孵育16 h时，全径P-C的吸收率为11%（乳糜颗粒的吸收率为80%），而9-顺式和13-顺式β -c的吸收率较低（2-3%）。在肝星状HSGT6细胞和来自大鼠肝脏的无细胞系统（微粒体）中也显示了全反式异构体的优先摄取，但在内皮细胞EAHY细胞或U937单核-巨噬细胞中没有。CaCo-2细胞对α -胡萝卜素（α -c）、叶黄素（LUT）和番茄红素（LYC）的吸收率分别为10%、7%和2.5%。LYC/ β - c和β - c / α - c之间存在明显的类胡萝卜素相互作用。目前的结果表明，P-C构象在其肠道吸收中起主要作用，顺式异构体的识别在细胞摄取和乳糜微粒结合的水平上。此外，细胞摄取和分泌P-C的动力学，肠道对一种类胡萝卜素的吸收被另一种类胡萝卜素的抑制，以及异构体识别的细胞特异性都表明，肠道细胞对类胡萝卜素的摄取是一个促进的过程。CaCo-2细胞的类胡萝卜素摄取和分泌：p -胡萝卜素异构体的选择性和类胡萝卜素的相互作用。
In presence of oleate and taurocholate, differentiated CaCo-2 cell monolayers on membranes were able to assemble and secrete chylomicrons. Under these conditions, both cellular uptake and secretion into chylomicrons of beta-carotene (beta-C) were curvilinear, time-dependent (2-16 h), saturable, and concentration-dependent (apparent K-m of 7-10 muM) processes. Under linear concentration conditions at 16 h incubation, the extent of absorption of all-trails P-C was 11% (80 % in chylomicrons), while those of 9-cis- and 13-cis-beta-C were significantly lower (2-3%). The preferential uptake of the all-trans isomer was also shown in hepatic stellate HSGT6 cells and in a cell-free system from rat liver (microsomes), but not in endothelial EAHY cells or U937 monocyte-macrophages. Moreover, extents of absorption of alpha-carotene (alpha-C), lutein (LUT), and lycopene (LYC) in CaCo-2 cells were 10%, 7%, and 2.5%, respectively. Marked carotenoid interactions were observed between LYC/beta-C and beta-C/alpha-C. The present results indicate that P-C conformation plays a major role in its intestinal absorption and that cis isomer discrimination is at the levels of cellular uptake and incorporation into chylomicrons. Moreover, the kinetics of cellular uptake and secretion of P-C, the inhibition of the intestinal absorption of one carotenoid by another, and the cellular specificity of isomer discrimination all suggest that carotenoid uptake by intestinal cells is a facilitated process. Carotenoid uptake and secretion by CaCo-2 cells: P-carotene isomer selectivity and carotenoid interactions.