Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Tokyo 113-8549, Japan.
J Bone Miner Metab. 2011 Nov;29(6):662-70. doi: 10.1007/s00774-011-0268-6. Epub 2011 Apr 19.
Osteocytes are embedded in the bone matrix, and they communicate with adjacent osteocytes, osteoblasts, and osteoclasts through the osteocyte lacunocanalicular system. Osteocytes are believed to be essential for the maintenance of bone homeostasis because they regulate mechanical sensing and mineral metabolism in mammalian bones; however, osteocyte morphology in other vertebrates has not been well documented. We conducted a comparative study on the morphology of osteocytes and the lacunocanalicular system of the following vertebrates: two teleost fishes [medaka (Oryzias latipes), and zebrafish (Danio rerio)], three amphibians [African clawed frog (Xenopus laevis), black-spotted pond frog (Rana nigromaculata), and Japanese fire-bellied newt (Cynops pyrrhogaster)], two reptiles [four-toed tortoise (Testudo horsfieldii) and green iguana (Iguana iguana)], and two mammals (laboratory mouse C57BL6 and human). The distribution of the osteocyte lacunocanalicular system in all these animals was investigated using the modified silver staining and the fluorescein-conjugated phalloidin staining methods. Bones of medaka had few osteocytes (acellular bone). Bones of zebrafish contained osteocytes (cellular bone) but had a poorly developed osteocyte lacunocanalicular system. Bones of Xenopus laevis, a freshwater species, and of other amphibians, reptiles, and mammals contained numerous osteocytes and a well-developed lacunocanalicular system. The present study indicates that development of the osteocyte lacunocanalicular system differs between teleost fishes and land vertebrates, but this pattern is not directly related to aquatic habitat.
骨细胞嵌入在骨基质中，通过骨细胞陷窝-小管系统与相邻的骨细胞、成骨细胞和破骨细胞进行通讯。骨细胞被认为对维持骨内环境稳定至关重要，因为它们调节哺乳动物骨骼中的机械感知和矿物质代谢；然而，其他脊椎动物的骨细胞形态尚未得到很好的记录。我们对以下脊椎动物的骨细胞形态和陷窝-小管系统进行了比较研究：两种硬骨鱼[斑马鱼（Danio rerio）和日本青鳉（Oryzias latipes）]、三种两栖动物[非洲爪蟾（Xenopus laevis）、黑斑蛙（Rana nigromaculata）和日本红腹蝾螈（Cynops pyrrhogaster）]、两种爬行动物[四爪陆龟（Testudo horsfieldii）和绿鬣蜥（Iguana iguana）]和两种哺乳动物（实验室小鼠 C57BL6 和人类）。使用改良的银染色和荧光素标记鬼笔环肽染色方法研究了所有这些动物的骨细胞陷窝-小管系统的分布。斑马鱼的骨骼中骨细胞较少（无细胞骨）。斑马鱼的骨骼含有骨细胞（有细胞骨），但骨细胞陷窝-小管系统发育不良。非洲爪蟾等淡水物种和其他两栖动物、爬行动物和哺乳动物的骨骼中含有大量的骨细胞和发育良好的陷窝-小管系统。本研究表明，硬骨鱼和陆地脊椎动物的骨细胞陷窝-小管系统的发育存在差异，但这种模式与水生栖息地没有直接关系。
