Pourlis Aris F, Antonopoulos John, Magras Ioannis N
Laboratory of Anatomy, Histology & Embryology, Veterinary School, University of Thessaly, 43100 Karditsa, Greece.
Ital J Anat Embryol. 2006 Jul-Sep;111(3):159-70.
The perichondral ossification of the limb long bones in the quail embryo is investigated, in this study, by means of light and electron microscopy. Longitudinal sections of the humerus, radius, ulna, femur, tibia and fibula stained with haematoxylin-eosin were examined by the light microscope. Ultrathin cross sections were selected for the electron microscope as well. Light microscopic analysis showed that the ossification began at the same time in the long bones of the wing and leg. At the embryonic day 6, all the cartilaginous rudiments consisted of three zones. The central zone composed of hypertrophic chondrocytes, a second zone on either side of the central zone, which consisted of flattened cells and a third zone, which represented the epiphyseal region. A thin sheath of osteoid and a bi-layered perichondrium-periosteum surrounded the central zone of the cartilaginous rudiments of the long bones. The perichondrium consisted of a layer of osteoblasts, in contact with the cartilage, and a layer of fibroblasts. At the embryonic day 7, the thickness of the calcified osteoid ring increased and a vasculature appeared between the layer of osteoblasts and the layer of fibroblasts. At the embryonic day 8, a second sheath of periosteal bone began to be formed. Concurrently, vascular and perivascular elements began to invade the cartilage. The ossification spread towards the distal ends of both the diaphysis. At the electron microscopic level, the osteoblasts of the perichondium showed cytoplasmatic characteristics of cells involved in protein synthesis. The perichondral ossification is the first hallmark of the osteogenesis in the long bones. The observations reported above, are in accordance with previous studies in the chick embryo.
在本研究中，通过光学显微镜和电子显微镜对鹌鹑胚胎肢体长骨的软骨膜骨化进行了研究。用苏木精-伊红染色的肱骨、桡骨、尺骨、股骨、胫骨和腓骨的纵切片由光学显微镜检查。也选择了超薄横截面用于电子显微镜检查。光学显微镜分析表明，翅膀和腿部的长骨同时开始骨化。在胚胎第6天，所有软骨雏形都由三个区域组成。中央区域由肥大软骨细胞组成，中央区域两侧的第二个区域由扁平细胞组成，第三个区域代表骨骺区域。一层类骨质和双层软骨膜-骨膜围绕着长骨软骨雏形的中央区域。软骨膜由一层与软骨接触的成骨细胞和一层成纤维细胞组成。在胚胎第7天，钙化类骨质环的厚度增加，并且在成骨细胞层和成纤维细胞层之间出现了脉管系统。在胚胎第8天，开始形成第二层骨膜骨。同时，血管和血管周围成分开始侵入软骨。骨化向骨干的远端扩散。在电子显微镜水平，软骨膜的成骨细胞表现出参与蛋白质合成的细胞的细胞质特征。软骨膜骨化是长骨成骨的第一个标志。上述观察结果与之前在鸡胚胎中的研究一致。
