Skutelsky E, Shoichetman T, Hammel I
Department of Pathology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Histochem Cell Biol. 1995 Dec;104(6):453-8. doi: 10.1007/BF01464335.
We used cationized colloidal gold in order to investigate the distribution of anionic sites in different secretory granules of rat and mouse mast cells. The localization of the anionic sites was performed by post-embedding labeling of thin sections of rat peritoneal cells or mouse skin tissue, fixed in Karnovsky's fixative and OsO4, and embedded in Araldite or LR white, respectively. In all cases anionic sites were demonstrated with a high density variation depending on cell type. In all mast cell secretory granules we have observed the highest density (ca. 500-900 gold particles/microns2), while in other peritoneal cell granules it was about 10 times less (ca. 40-80 gold particles/microns2). Pretreatment of the LR white sections with heparinase I and III resulted in a reduction of 97% and 72%, respectively, in the binding of the gold particles to the granules, indicating that the majority of the gold binding reactivity is due to heparin. Correlation of section profile area with labeling density revealed that the smaller granules were significantly more labeled when compared to the larger profiles. On the basis of these observations it seems that a post-translational change (mainly sulfation of heparin) of secretory content influences the granule anionic charge and thus may affect the intragranule buffer capacity.
我们使用阳离子化胶体金来研究大鼠和小鼠肥大细胞不同分泌颗粒中阴离子位点的分布。阴离子位点的定位是通过对大鼠腹膜细胞或小鼠皮肤组织的薄片进行包埋后标记来完成的，这些组织分别用卡诺夫斯基固定液和四氧化锇固定，并分别包埋在环氧树脂或LR白色树脂中。在所有情况下，根据细胞类型，阴离子位点显示出高密度变化。在所有肥大细胞分泌颗粒中，我们观察到最高密度（约500 - 900个金颗粒/平方微米），而在其他腹膜细胞颗粒中，密度约为其十分之一（约40 - 80个金颗粒/平方微米）。用肝素酶I和III对LR白色切片进行预处理后，金颗粒与颗粒的结合分别减少了97%和72%，这表明金结合反应的大部分是由于肝素。切片轮廓面积与标记密度的相关性表明，与较大轮廓相比，较小的颗粒标记明显更多。基于这些观察结果，似乎分泌内容物的翻译后变化（主要是肝素的硫酸化）会影响颗粒的阴离子电荷，从而可能影响颗粒内的缓冲能力。
