Swartzendruber D C
Marshall Dermatology Research Laboratories, Department of Dermatology, University of Iowa College of Medicine, Iowa City 52242.
Semin Dermatol. 1992 Jun;11(2):157-61.
Ruthenium tetroxide fixation has permitted the electron microscopic visualization of intercellular lipid lamellae in thin sections of stratum corneum. This development complements prior freeze-fracture studies of lipid lamellae and has advanced our knowledge about the ultrastructure of epidermal lipids in several ways. We have demonstrated a continuous lipid envelope that surrounds each differentiated stratum corneum cell and the presence of lipid lamellae throughout the entire stratum corneum of three mammalian species, including humans. Wherever lamellae are seen, they are present in multiples of one, two, or more pairs of bilayers, consistent with their formation from fused, flattened lipid vesicles. A unique pattern of lipid monolayers intervening between each pair of bilayers, based on sharing lipid chains between bilayers, has been proposed. In regions where there are no intercellular lamellae between corneocytes, intervening monolayers are in contact with adjacent lipid envelopes that might be involved in stratum corneum cohesion. However, limitations to the ruthenium technique must be overcome before changes in lamellar patterns can be accurately attributed to, or correlated with, changes in permeability brought about by experimental procedures or in diseased states.
四氧化钌固定法已能在角质层薄片中通过电子显微镜观察到细胞间脂质层。这一进展补充了先前对脂质层的冷冻断裂研究，并在多个方面推进了我们对表皮脂质超微结构的认识。我们已经证明，在包括人类在内的三种哺乳动物的整个角质层中，存在围绕每个分化的角质层细胞的连续脂质包膜以及脂质层。无论在何处看到脂质层，它们都以一对、两对或更多对双层的倍数形式存在，这与它们由融合、扁平的脂质小泡形成一致。基于双层之间共享脂质链，有人提出了一种在每对双层之间插入脂质单层的独特模式。在角质形成细胞之间不存在细胞间层的区域，中间的单层与可能参与角质层黏附的相邻脂质包膜接触。然而，在能够准确地将层状模式的变化归因于实验程序或疾病状态引起的通透性变化，或将其与之关联之前，必须克服钌技术的局限性。
