Retinol transport in cultured fat-storing cells of rat liver. Quantitative analysis by anchored cell analysis and sorting system.
Retinol transport in cultured fat-storing cells of rat liver. Quantitative analysis by anchored cell analysis and sorting system.
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发表时间：
1989-07
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通讯作者：
T. Matsuura;S. Nagamori;K. Fujise;S. Hasumura;S. Homma;H. Sujino;K. Shimizu;M. Niiya;H. Kameda;K. Hirosawa
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作者：
T. Matsuura;S. Nagamori;K. Fujise;S. Hasumura;S. Homma;H. Sujino;K. Shimizu;M. Niiya;H. Kameda;K. Hirosawa
维生素A在脂肪储存细胞（FSC）体内的特异性转运机制尚不清楚。本研究利用维生素A发出的自发荧光定量分析添加到培养基中的维生素A在培养的FSCs中的转运情况。用38% Percoll密度梯度离心，从正常大鼠肝细胞中分离出富含fsc的部分。在培养的第3天和第4天，观察到FSCs仍保留细胞质脂肪滴。通过检测含有脂肪滴的FSCs对维生素A荧光的发射，选择其用于本实验。为了分析离体细胞的维生素A含量，我们使用了一种新开发的锚定细胞分析和分选系统（ACAS 470），该系统在相差显微镜下利用激光对贴壁细胞进行荧光分析和分选，其照射范围缩小到1微米。该系统在培养的FSCs中也能检测到维生素A荧光。FSC在添加1 × 10(-6) M维生素A的培养基中培养24小时后，每个FSC的荧光强度为对照24.3 +/- 11.2 × 10(5)/细胞，醋酸视黄酯为61.5 +/- 17.6 × 10(5)/细胞，棕榈酸视黄酯为26.0 +/- 12.6 × 10(5)/细胞，视黄醇为59.0 +/- 15.1 × 10(5)/细胞。因此，在没有视黄醇结合蛋白参与的情况下，视黄醇和醋酸视黄酯被大量转移到FSCs中。此外，对本研究中观察到的视黄醇转运机制进行了进一步的研究。运输从未被维生素E或叠氮化物所抑制。视黄醇可能通过浓度梯度的被动转运转运，而不是通过视黄醇本身的主动转运或通过细胞膜损伤转运。在胎牛血清中有抑制视黄醇进入细胞的趋势。这种抑制可能是因为视黄醇结合蛋白或其他血清蛋白降低了游离视黄醇的浓度。
It is difficult to study the mechanism of specific transport of vitamin A in fat-storing cells (FSC) in vivo. In this study, transport of vitamin A added to the medium was quantitatively analyzed in cultured FSCs by means of the spontaneous fluorescence emitted by vitamin A. By density-gradient centrifugation with 38% Percoll, an FSC-rich fraction was separated from normal rat liver cells. The FSCs were observed to retain cytoplasmic fat droplets even on days 3 and 4 of culture. The FSCs containing fat droplets were selected for this experiment by checking their emission of vitamin A fluorescence. To analyze the vitamin A content of isolated cells, we employed a newly developed anchored cell analysis and sorting system (ACAS 470), which provides fluorescence analysis and sorting of adherent cells under the phase contrast microscope by utilizing a laser with its irradiation range narrowed to 1 micron. Vitamin A fluorescence was detectable by this system even in the cultured FSCs. After 24 hours of culture of FSCs in medium with 1 x 10(-6) M vitamin A added, the strength of fluorescence per FSC was 24.3 +/- 11.2 x 10(5)/cell for control, 61.5 +/- 17.6 x 10(5)/cell for retinyl acetate, 26.0 +/- 12.6 x 10(5)/cell for retinyl palmitate, and 59.0 +/- 15.1 x 10(5)/cell for retinol. Thus, retinol and retinyl acetate were transferred to FSCs in significant amounts without the participation of retinol-binding protein. Furthermore, an extended examination was made of the mechanism of the retinol transport observed in this study. Transport was never inhibited by the presence of vitamin E or azide. Retinol may be transferred by passive transport attributable to the concentration gradient rather than by active transport or through cell membrane damage by retinol itself. There was a tendency for inhibition of the transport of retinol into the cells in fetal calf serum. This inhibition may have occurred because the retinol-binding protein or other serum proteins had decreased the concentration of free retinol.