Koonen D P Y, Coumans W A, Arumugam Y, Bonen A, Glatz J F C, Luiken J J F P
Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands.
Mol Cell Biochem. 2002 Oct;239(1-2):121-30.
In order to use giant vesicles for substrate uptake studies in metabolically important tissues, we characterized giant vesicles isolated from heart, liver, skeletal muscle and adipose tissue. We investigated which cell types and which plasma membrane regions are involved in giant vesicle formation and we examined the presence of transporters for metabolic substrates. Analysis of giant vesicles with markers specific for distinct cell types and distinct domains of the plasma membrane reveals that the plasma membrane of parenchymal cells, but not endothelial cells, are the source of the vesicle membranes. In addition, plasma membrane regions enriched in caveolae and involved in docking of recycling vesicles from the endosomal compartment are retained in giant vesicles, indicating that KCl-induced alterations in recycling processes are involved in giant vesicle formation. Giant vesicles contain vesicular lumen consisting of the soluble constituents of the cytoplasm including, fatty-acid binding proteins. Furthermore, giant vesicles isolated from heart, liver, skeletal muscle and adipose tissue are similar in size (10-15 microm) and shape and do not contain subcellular organelles, providing the advantage that substrate fluxes in the different organs can be studied independently of the surface/volume ratio but most importantly in the absence of intracellular metabolism.
为了将巨型囊泡用于代谢重要组织的底物摄取研究，我们对从心脏、肝脏、骨骼肌和脂肪组织分离出的巨型囊泡进行了表征。我们研究了哪些细胞类型和哪些质膜区域参与巨型囊泡的形成，并检测了代谢底物转运蛋白的存在情况。用针对不同细胞类型和质膜不同结构域的特异性标记物对巨型囊泡进行分析，结果表明实质细胞的质膜而非内皮细胞的质膜是囊泡膜的来源。此外，富含小窝且参与内体区室回收囊泡对接的质膜区域保留在巨型囊泡中，这表明氯化钾诱导的回收过程改变参与了巨型囊泡的形成。巨型囊泡含有由细胞质可溶性成分组成的囊泡腔，包括脂肪酸结合蛋白。此外，从心脏、肝脏、骨骼肌和脂肪组织分离出的巨型囊泡在大小（10 - 15微米）和形状上相似，且不包含亚细胞器，这提供了一个优势，即可以独立于表面积/体积比来研究不同器官中的底物通量，但最重要的是在没有细胞内代谢的情况下进行研究。
