Howlett C R
J Anat. 1980 Jun;130(Pt 4):745-68.
The ultrastructure of endochondral osteogenesis from the proximal end of tibias of 7 weeks old normal White Leghorn and broiler chickens is described. Little, if any, ultrastructural differences exists between these two strains of birds. In the growth plate, proliferation of chondrocytes and their matriceal production is approximately matched by resorption. Erosion of the metaphyseal aspect of the growth plate is accomplished under two sets of circumstances: firstly, when mineralization of the cartilaginous matrix is so scanty as to be discernible only by electron microscopy, and secondly, when calcification is gross and easily appreciated by light microscopy. The former process appears to be accomplished in the main by perivascular mononuclear cells and the latter, to a great extent, by chondroclasts. It appears that metaphyseal blood vessels expand, by saccular protrusions, into pre-existing spaces or those created by cellular erosion. Cones or plates of calcified cartilage, which extend into the metaphysis, act as a template for initial deposition of bone. Osteoblasts recently surrounded by osteoid have adjacent to their plasmalemma a pericellular sheath which is composed of ill-defined clumps of amorphous material as well as some incompletely aggregated collagenous fibrils. Beyond this sheath collagenous fibrils and fibres, with distinct periodicities (ranging from 57 to 69 nm) are observed. Towards the diaphysis the range of the periodicity of fibres in osteoid narrows to 64-69 nm.
描述了7周龄正常白来航鸡和肉鸡胫骨近端软骨内成骨的超微结构。这两种品系的鸡之间几乎不存在超微结构差异。在生长板中，软骨细胞的增殖及其基质产生与吸收大致匹配。生长板干骺端的侵蚀在两种情况下完成：第一，当软骨基质矿化极少以至于只能通过电子显微镜才能辨别时；第二，当钙化明显且通过光学显微镜很容易观察到时。前一过程主要由血管周围单核细胞完成，而后一过程在很大程度上由破软骨细胞完成。干骺端血管似乎通过囊状突起扩张进入先前存在的空间或由细胞侵蚀形成的空间。延伸至干骺端的钙化软骨锥体或板充当骨初始沉积的模板。最近被类骨质包围的成骨细胞在其质膜附近有一个细胞周鞘，该鞘由不明确的无定形物质团块以及一些未完全聚集的胶原纤维组成。在这个鞘之外，可以观察到具有不同周期性（范围从57到69纳米）的胶原纤维和纤维束。朝向骨干，类骨质中纤维的周期性范围缩小到64 - 69纳米。
