Yokota S, Tsuji H, Kato K
Histochemistry. 1985;82(2):141-8. doi: 10.1007/BF00708198.
Light and electron microscopic localization of cathepsin D in rat liver was investigated by post-embedding immunoenzyme and protein A-gold techniques. By light microscopy, cytoplasmic granules of parenchymal cells and Kupffer cells were stained for cathepsin D. Weak staining was also noted in sinusoidal endothelial cells. In the parenchymal cells many of positive granules located around bile canaliculi. In the Kupffer cells and the endothelial cells, diffuse staining was noted in the cytoplasm in addition to granular staining. By electron microscopy, gold particles representing the antigenic sites for cathepsin D were seen in typical secondary lysosomes and some multivesicular bodies of the parenchymal cells and Kupffer cells. The lysosomes of the endothelial cells and fat-storing cells were weakly labeled. Quantitative analysis of the labeling density in the lysosomes of these three types of cells demonstrated that the lysosomes of parenchymal cells and Kupffer cells are main containers of cathepsin D in rat liver. The results suggest that cathepsin D functions in the intracellular digestive system of parenchymal cells and Kupffer cells but not so much in that of the endothelial cells.
采用包埋后免疫酶法和蛋白A-金技术研究了大鼠肝脏中组织蛋白酶D的光镜和电镜定位。光镜下，实质细胞和库普弗细胞的胞质颗粒被组织蛋白酶D染色。在窦状内皮细胞中也观察到弱阳性染色。在实质细胞中，许多阳性颗粒位于胆小管周围。在库普弗细胞和内皮细胞中，除颗粒状染色外，细胞质中还可见弥漫性染色。电镜下，在实质细胞和库普弗细胞的典型次级溶酶体和一些多泡体中可见代表组织蛋白酶D抗原位点的金颗粒。内皮细胞和贮脂细胞的溶酶体标记较弱。对这三种细胞溶酶体中标记密度的定量分析表明，实质细胞和库普弗细胞的溶酶体是大鼠肝脏中组织蛋白酶D的主要储存部位。结果表明，组织蛋白酶D在实质细胞和库普弗细胞的细胞内消化系统中起作用，但在内皮细胞中作用不大。
