Norton W T, Abe T, Poduslo S E, DeVries G H
J Neurosci Res. 1975;1(1):57-75. doi: 10.1002/jnr.490010106.
The current status of the published work on the lipid composition of isolated brain cells is reviewed and some new work on the sphingolipids of these cells is presented. In spite of considerable differences in isolation techniques between different groups, the lipid analyses of different cell preparations are similar enough to permit several generalizations. This fact is an encouraging sign that cell separation methods have considerable usefulness in defining the composition of normal brain cells. It is a general finding that astrocytes have more lipid than neuronal perikarya but that the gross lipid composition of these two cell types is surprisingly similar. Oligodendroglial lipids are quite different from those of the other two cell types and are characterized by a high galactolipid content. Although such a lipid pattern might be expected in oligodendroglia, which are myelin-forming cells, axonal lipids have an even higher galactolipid content. In an effort to find more cell-specific patterns, the glycosphingolipids were examined in more detail. Differences were seen in the distribution and fatty-acid patterns of these minor lipids in neurons and astrocytes, although it may be premature to conclude that these differences will prove to be cell-specific. All of the isolated cells were found to contain galactosylceramide, sulfatide, glucosylceramide, dihexosylceramide, and gangliosides. The distribution of these lipids in the normal cells was found to differ considerably from that reported in cultured neuroblastoma cells or astrocytoma cells. Not only were gangliosides present in all cells but the ganglioside patterns of neurons and astrocytes were nearly identical. The fatty-acid patterns of the neuronal and astroglial sphingolipids generally do not resemble each other, and both are quite different from those found in oligodendroglia and axons. However, the fatty-acid composition of the sphingolipids from bovine oligodendroglia and from axons are similar and resemble those of myelin lipids. The fatty acids of glucosylceramide and dihexosylceramide are similar in all three cell types. They have rather large amounts of 16:0 and acids longer than C18; thus they are considerably different from the ganglioside fatty acids (which have mostly 15:0) isolated from the same fractions.
本文综述了已发表的关于分离脑细胞脂质组成的研究现状，并展示了一些关于这些细胞鞘脂的新研究成果。尽管不同研究小组在分离技术上存在显著差异，但不同细胞制剂的脂质分析结果足够相似，从而可以得出一些一般性结论。这一事实是一个令人鼓舞的迹象，表明细胞分离方法在确定正常脑细胞组成方面具有相当大的用途。一个普遍的发现是，星形胶质细胞比神经元胞体含有更多的脂质，但这两种细胞类型的总体脂质组成惊人地相似。少突胶质细胞的脂质与其他两种细胞类型的脂质有很大不同，其特点是半乳糖脂含量高。虽然在形成髓鞘的少突胶质细胞中可能会出现这样的脂质模式，但轴突脂质的半乳糖脂含量甚至更高。为了找到更多细胞特异性模式，对糖鞘脂进行了更详细的研究。在神经元和星形胶质细胞中，这些次要脂质的分布和脂肪酸模式存在差异，不过现在就得出这些差异将被证明具有细胞特异性的结论可能还为时过早。所有分离出的细胞都被发现含有半乳糖基神经酰胺、硫脂、葡萄糖基神经酰胺、二己糖基神经酰胺和神经节苷脂。这些脂质在正常细胞中的分布与培养的神经母细胞瘤细胞或星形细胞瘤细胞中报道的分布有很大差异。不仅所有细胞中都存在神经节苷脂，而且神经元和星形胶质细胞的神经节苷脂模式几乎相同。神经元和星形胶质细胞鞘脂的脂肪酸模式通常彼此不同，并且都与少突胶质细胞和轴突中的脂肪酸模式有很大差异。然而，来自牛少突胶质细胞和轴突的鞘脂的脂肪酸组成相似，并且与髓磷脂脂质的脂肪酸组成相似。在所有三种细胞类型中，葡萄糖基神经酰胺和二己糖基神经酰胺的脂肪酸相似。它们含有相当大量的16:0和比C18长的酸；因此，它们与从相同组分中分离出的神经节苷脂脂肪酸（主要含有15:0）有很大不同。
