Histochemical studies on glycolipids especially from functional and developmental aspects

用激光共聚焦扫描显微镜和透射电子显微镜研究了各种糖脂在大鼠肾脏和小肠中的组织化学定位。从正常Wistar大鼠和糖尿病Goto-Kakizaki(GK)大鼠分离标本，分别用抗Gb3或神经节苷脂(GM1、GD2、GQ1b、GD3、GD1a、GM3、o-乙酰基-GD3)的小鼠单抗处理后，分别用Cy3标记的二抗进行共聚焦显微镜观察和用HRP标记的抗体进行电子显微镜观察。在小肠中，一些神经节苷脂(GD2、GQ1b等)积聚。在肌间神经丛的神经细胞体周围和内环平滑肌细胞的质膜上也可观察到。肠腺上皮细胞，尤其是其基侧质膜呈Gb3阳性。在正常肾皮质中，以肾小球和尿小管上皮细胞为最多，各抗体均有不同的分布模式。与正常Wistar大鼠相比，GK大鼠肾小球中抗Gb3和抗GD1a抗体染色增强。电镜观察发现，GK大鼠肾小球基底膜、足细胞质膜和内皮细胞质膜是抗Gb3抗体的结合部位。糖脂在大鼠肾皮质中的特殊分布及其在糖尿病后的变化可能为了解肾功能尤其是肾小球区的功能提供一些重要线索。

Histochemical localizations of various kinds of glycolipids in rat kidney and small intestine were investigated with the use of confocal laser scanning microscopy and transmission electron microscopy. Samples were isolated from normal Wistar rats and diabetic Goto-Kakizaki(GK)rats and were treated with mouse monoclonal antibodies(mAbs) against globoside(Gb3) or gangliosides(GM1, GD2, GQ1b, GD3, GD1a, GM3, o-acetyl-GD3) followed by treatment with Cy3-labeled secondary antibody for confocal microscopy and HRP-labeled antibody for electron microscopy, respectively. In the case of small intestine, accumulations of some gangliosides (GD2, GQ1b etc.) were observed around the nerve cell body in the myenteric plexus and also along the plasma membranes of inner-circular smooth muscle cells. Intestinal gland epithelial cells, especially their basolateral plasma membranes were positive for globoside (Gb3). In normal kidney cortex, each antibody revealed specific distribution pattern especially in glomeruli and in urinary tubular epithelial cells. In GK rats, anti-Gb3 and anti-GD1a antibodies demonstrated increased stainability for glomeruli compared with those in normal Wistar rats. Electron microscopical observation revealed that, the binding sites of anti-Gb3 in GK rats were glomerular basement membranes and the plasma membranes of podocytes and endothelial cells. Specific distributions of glycolipids in rat kidney cortex and their changes following diabetic disorder may provide some important clues for understanding renal functions especially in glomerular area.