Ferretti G, Zolese G, Curatola G, Jezequel A M, Benedetti A
Institute of Biochemistry, Faculty of Medicine, University of Ancona, Italy.
Biochim Biophys Acta. 1993 Apr 22;1147(2):245-50. doi: 10.1016/0005-2736(93)90009-o.
The fluorescence decay of 1,6-diphenyl-1,3,5-hexatriene (DPH) and of 1-(4-trimethylammonium-phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) has been studied in hepatocytes isolated from rat liver and in isolated plasma membrane subfractions (cLPM, canalicular membranes and bLPM, basolateral membranes) using frequency domain fluorometry. The decay has been analyzed either by using a model of discrete exponential components or a model that assumes a continuous distribution of lifetime values in order to study different aspects of membrane heterogeneity. The results obtained by the two analyses are practically superimposable but the distributional approach allows an evaluation of membrane heterogeneity through the width of the distribution that has shown particularly significant differences when freshly hepatocytes are compared with in vitro aged hepatocytes. Moreover, the comparison of the distributional analysis of the two probes has shown in cLPM a tendency to higher values of the main lifetime component and a narrower distribution width with respect to bLPM. These results indicate changes of membrane domain organization that have been discussed in relation with the specific lipid composition that characterizes the two membrane subfractions. Our results indicate that frequency domain fluorometry may be used to study membrane heterogeneity in intact cells and isolated membranes.
利用频域荧光分析法，对从大鼠肝脏分离出的肝细胞以及分离出的质膜亚组分（胆小管质膜、胆小管膜和基底外侧质膜、基底外侧膜）中1,6 - 二苯基 - 1,3,5 - 己三烯（DPH）和1 - （4 - 三甲基铵苯基） - 6 - 苯基 - 1,3,5 - 己三烯（TMA - DPH）的荧光衰减进行了研究。通过使用离散指数成分模型或假定寿命值呈连续分布的模型对衰减进行分析，以便研究膜异质性的不同方面。两种分析得到的结果实际上是可叠加的，但分布方法允许通过分布宽度评估膜异质性，当将新鲜肝细胞与体外老化肝细胞进行比较时，分布宽度显示出特别显著的差异。此外，对两种探针的分布分析比较表明，在胆小管质膜中，相对于基底外侧质膜，主要寿命成分的值有升高趋势且分布宽度更窄。这些结果表明膜结构域组织发生了变化，已结合表征这两种膜亚组分的特定脂质组成进行了讨论。我们的结果表明，频域荧光分析法可用于研究完整细胞和分离膜中的膜异质性。
