PLASMA-MEMBRANE FLUIDITY IN ISOLATED RAT HEPATOCYTES - A COMPARATIVE-STUDY USING DPH AND TMA-DPH AS FLUORESCENT-PROBES
PLASMA-MEMBRANE FLUIDITY IN ISOLATED RAT HEPATOCYTES - A COMPARATIVE-STUDY USING DPH AND TMA-DPH AS FLUORESCENT-PROBES
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DOI：
10.1111/j.1440-1746.1989.tb00829.x
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发表时间：
1989-05-01
影响因子：
4.1
通讯作者：
ORLANDI, F
中科院分区：
文献类型：
--
作者：
BENEDETTI, A;FERRETTI, G;ORLANDI, F
膜流动性的研究是一个迅速发展的研究领域，近年来引起了肝脏学的关注。本研究首次报道了大鼠肝细胞膜流动性的测定。这些数据已经与来自匀浆的质膜组分和亚组分(基侧或管状)的数据进行了比较。用来测量流动性的荧光探针是经典的二苯基己三烯(DPH)及其在25℃和37℃下的衍生物三甲基氨基-苯基己三烯(TMA-DPH)。DPH的测量结果低于TMA-DPH，这可能是由于探针在磷脂双层不同区域的定位所致。此外，DPH在分离的肝细胞中获得的荧光偏振值与膜组分相比有显著差异，这与TMA-DPH相反，TMA-DPH的各个值都是相同的数量级。这种行为可能是由于DPH在膜核心的移动性和它快速内化到细胞内，而TMA-DPH长期固定在细胞表面。这些结果表明，TMA-DPH是一种比DPH更好的测量整个离体肝细胞荧光偏振度的探针，使用不同的探针可能有助于探索膜双层的不同区域。
The study of membrane fluidity is a rapidly expanding field of research and its interest in hepatology has been stressed recently. The present study is the first report concerned with the determination of membrane fluidity of isolated rat hepatocytes. The data have been compared with those obtained in plasma membrane fractions and subfractions (basolateral or canalicular) derived from homogenates. The fluorescent probes used to measure the fluidity were diphenylhexatriene (DPH) a ‘classical’ probe, and its derivative trimethylammoniodi‐phenxylhexatriene (TMA‐DPH) at 25°C and at 37°C. The values obtained with DPH were lower than those with TMA‐DPH, probably due to the localization of the probes in different regions of the phospholipid bilayer. In addition, DPH revealed significant differences in the fluorescence polarization values obtained in isolated hepatocytes compared with membrane fractions, which was in contrast to TMA‐DPH, where the respective values were of the same order of magnitude. This behaviour is probably due to the mobility of DPH in the membrane core and its rapid internalization into the cell, whereas TMA‐DPH remains anchored for a long time on the cell surface. These findings suggest that TMA‐DPH is a better probe than DPH for measuring the fluorescence polarization of whole isolated hepatocytes and that the use of different probes might be of help in exploring different zones of the membrane bilayer.