Maguchi S, Gasa S, Matsushima J, Saga Y, Kawano M, Makita A
Department of Otolaryngology, Hokkaido University, Sapporo, Japan.
Auris Nasus Larynx. 1991;18(1):1-8. doi: 10.1016/s0385-8146(12)80244-6.
In recent years, the functions of glycolipids have been intensively studied. Before the research of the roles of glycolipids in the inner ear, it seemed to be necessary to demonstrate the composition of glycolipids at first. Therefore, rat cochlea has been examined for glycolipid composition in the present study. Glycolipids extracted from 200 cochlea samples were separated into neutral and acidic glycolipid fractions. Each fraction was analyzed by thin-layer chromatography. The neutral glycolipid was almost exclusively galactosylceramide (cerebroside) with trace amounts of globoside and unidentified glycolipids. In acidic glycolipids, sulfated galactosylceramide (cerebroside sulfate) was most abundant. Of the gangliosides (sialic acid-containing glycolipids), ganglioside GM3 (51.8%) was the predominant component, and GM2 (6.0%), GM1 (8.8%), GD3 (10.7%), GD1a (8.7%), GD1b (5.9%), and GT1b (3.6%) were also detected. In addition to these, rat cochlea also contained several, minor, unidentified gangliosides. This pattern of the cochlear acidic glycolipids is very similar to that of the renal acidic glycolipids. This finding seems to be very interesting when considering that the toxic side effects of aminoglycosides occur only in the kidney and the inner ear.
近年来，糖脂的功能得到了深入研究。在研究糖脂在内耳中的作用之前，似乎有必要首先阐明糖脂的组成。因此，在本研究中对大鼠耳蜗的糖脂组成进行了检测。从200个耳蜗样本中提取的糖脂被分离为中性和酸性糖脂组分。每个组分通过薄层色谱法进行分析。中性糖脂几乎全部是半乳糖神经酰胺（脑苷脂），含有痕量的红细胞糖苷脂和未鉴定的糖脂。在酸性糖脂中，硫酸化半乳糖神经酰胺（硫酸脑苷脂）最为丰富。在神经节苷脂（含唾液酸的糖脂）中，神经节苷脂GM3（51.8%）是主要成分，还检测到GM2（6.0%）、GM1（8.8%）、GD3（10.7%）、GD1a（8.7%）、GD1b（5.9%）和GT1b（3.6%）。除此之外，大鼠耳蜗还含有几种少量的、未鉴定的神经节苷脂。耳蜗酸性糖脂的这种模式与肾酸性糖脂的模式非常相似。考虑到氨基糖苷类药物的毒副作用仅发生在肾脏和内耳，这一发现似乎非常有趣。
