Takagi M, Parmley R T, Denys F R
Lab Invest. 1981 Feb;44(2):116-26.
Secretory granules of chondrocytes contain a variety of complex carbohydrates, which include glycosaminoglycans and glycoproteins necessary for the formation of the cartilage matrix. The present study has utilized ultrastructural, cytochemical, and radioautographic methods to determine the subcellular route of incorporation of sulfated and vicinal glycol-containing complex carbohydrates into secretory granules and their subsequent distribution in granules. High iron diamine specifically stained sulfated glycoconjugates in Golgi saccules, Golgi derived vacuoles, and mature secretory granules. Incubation of chondrocytes with 35SO4 resulted in significant radioautographic labeling of Golgi saccules, condensing vacuoles, intermediate granules containing moderately dense amorphous material, and mature granules containing fibrillar material. Periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining of unosmicated thin sections localized vicinal glycol-containing glycoconjugates in cisternae of rough endoplasmic reticulum and coated vesicles, some of which appeared to be budding from rough endoplasmic reticulum. Similar coated vesicles appeared to fuse with condensing vacuoles and granules of intermediate maturity which evidenced moderate PA-TCH-SP reactivity. These vesicles were very seldom seen associated with Golgi saccules which contained 35SO4 radiolabels and high iron diamine reactivity but lacked significant PA-TCH-SP staining. The PA-TCH-SP-positive vesicles were not associated with mature secretory granules which demonstrated strong PA-TCH-SP staining. Lysosomes demonstrated moderately heavy PA-TCH-SP staining. Amylase digestion of en bloc specimens removed all PA-TCH-SP reactive cytoplasmic glycogen, however, staining of cytoplasmic organelles was not decreased. These studies indicate that sulfated glycosaminoglycans and vicinal glycol-containing glycoproteins are transported to secretory granules by Golgi saccules and coated vesicles, respectively, and are subsequently distributed differently within the maturing secretory granules.
软骨细胞的分泌颗粒含有多种复杂碳水化合物，其中包括形成软骨基质所需的糖胺聚糖和糖蛋白。本研究利用超微结构、细胞化学和放射自显影方法，确定含硫酸化和连位二醇的复杂碳水化合物掺入分泌颗粒的亚细胞途径及其在颗粒中的后续分布。高铁二胺特异性地染色了高尔基体囊泡、高尔基体衍生的液泡和成熟分泌颗粒中的硫酸化糖缀合物。用35SO4孵育软骨细胞导致高尔基体囊泡、浓缩液泡、含有中度致密无定形物质的中间颗粒以及含有纤维状物质的成熟颗粒出现明显的放射自显影标记。未固定薄切片的高碘酸-硫代碳酰肼-银蛋白染色（PA-TCH-SP）将含连位二醇的糖缀合物定位在粗面内质网的池和被膜小泡中，其中一些似乎是从粗面内质网出芽形成的。类似的被膜小泡似乎与浓缩液泡和中等成熟度的颗粒融合，这些颗粒显示出中度的PA-TCH-SP反应性。这些小泡很少与含有35SO4放射性标记和高铁二胺反应性但缺乏明显PA-TCH-SP染色的高尔基体囊泡相关联。PA-TCH-SP阳性小泡与显示强PA-TCH-SP染色的成熟分泌颗粒不相关。溶酶体显示中度较强的PA-TCH-SP染色。对整装标本进行淀粉酶消化去除了所有PA-TCH-SP反应性的细胞质糖原，然而，细胞质细胞器的染色并未减少。这些研究表明，硫酸化糖胺聚糖和含连位二醇的糖蛋白分别通过高尔基体囊泡和被膜小泡转运到分泌颗粒中，随后在成熟的分泌颗粒中分布不同。
