Blanchette-Mackie E J, Scow R O
J Lipid Res. 1983 Mar;24(3):229-44.
Lipolysis occurred and lamellar structures with a periodicity of 40 A developed in glutaraldehyde-fixed brown adipose tissue of suckling rats when the tissue was incubated at 25 degrees C. The lamellar structures were found in capillaries, associated with chylomicrons, in intracellular channels of capillary endothelium, in extracellular space, and in channels near lipid droplets in adipocytes in tissue of fed rats injected intravenously with chylomicrons. They were also found in channels near mitochondria and inside mitochondria in adipocytes in incubated-fixed tissue of rats exposed to 4 degrees C for 2 hr or unsuckled overnight. In addition, aqueous spaces developed adjacent to lipid droplets in incubated tissue of cold-exposed and unsuckled rats. Development of lamellar structures under conditions causing lipolysis and accumulation of fatty acids in fixed tissue indicated the lamellae were composed primarily of fatty acids. We conclude that fatty acids formed by lipolysis of chylomicrons in tissue from fed rats accumulated in a continuum of the outer leaflets of cell membranes extending from capillary lumen to lipid droplets of adipocytes, and fatty acids formed by lipolysis of intracellular lipid in tissue from cold-exposed or unsuckled rats accumulated mostly in a continuum extending from lipid droplets to the interior of mitochondria. When fatty acids overcrowded the continuum in fixed tissue, they formed lamellar extensions of the continuum at different sites along its course through the tissue.
在25摄氏度孵育时，戊二醛固定的乳鼠棕色脂肪组织中发生了脂解作用，并形成了周期为40埃的层状结构。在喂食大鼠静脉注射乳糜微粒后的组织中，在毛细血管、与乳糜微粒相关的部位、毛细血管内皮细胞的细胞内通道、细胞外间隙以及脂肪细胞中脂滴附近的通道中都发现了层状结构。在暴露于4摄氏度2小时或未哺乳过夜的大鼠的孵育固定组织中，也在脂肪细胞的线粒体附近通道和线粒体内发现了层状结构。此外，在冷暴露和未哺乳大鼠的孵育组织中，脂滴附近出现了水相空间。在导致固定组织中脂解和脂肪酸积累的条件下层状结构的形成表明，这些层主要由脂肪酸组成。我们得出结论，喂食大鼠组织中乳糜微粒脂解形成的脂肪酸在从毛细血管腔延伸至脂肪细胞脂滴的细胞膜外小叶连续区域中积累，而冷暴露或未哺乳大鼠组织中细胞内脂质脂解形成的脂肪酸大多在从脂滴延伸至线粒体内的连续区域中积累。当脂肪酸在固定组织中使连续区域过于拥挤时，它们会在该连续区域贯穿组织的不同部位形成层状延伸。
