Hattori H, Kawai M, Yasue K, Mizutani H, Kobayashi M, Kaneda T, Hoshino T
Department of Oral Surgery, Nagoya University School of Medicine, Japan.
J Electron Microsc (Tokyo). 1993 Dec;42(6):400-6.
Bone morphogenetic protein (BMP) partially purified from bovine bone was implanted into the thigh muscles of AKR-strain mice to induce an ectopic endochondral ossification tissue. The extracellular matrix components around the hypertrophic chondrocytes in the induced tissue were examined by electron microscopy and immunohistochemistry for type I collagen. At 14 days after implantation, chondrocytes became hypertrophic with calcifying matrix around them. Some hypertrophic chondrocytes showed no degenerative appearances. They were ringed by a pericellular matrix with no metachromasia which was distinct from the metachromatic cartilage matrix. The localization of type I collagen was demonstrated by immuno-staining in this matrix. Ultrastructurally, ring-shaped matrix consisted of interwoven collagen fibrils on which a D-periodic banding pattern could be discerned. Immunoelectron microscopy demonstrated immunoreactivity of type I collagen on these fibrils. These results suggest that some of the BMP-induced hypertrophic chondrocytes maintain their activity and produce type I collagen-rich matrix before their lacunae are eroded.
从牛骨中部分纯化得到的骨形态发生蛋白（BMP）被植入AKR品系小鼠的大腿肌肉中，以诱导异位软骨内成骨组织形成。通过电子显微镜和I型胶原免疫组织化学方法，对诱导组织中肥大软骨细胞周围的细胞外基质成分进行了检测。植入后14天，软骨细胞肥大，周围基质钙化。一些肥大软骨细胞未出现退变表现。它们被无异染性的细胞周基质环绕，该基质与异染性软骨基质不同。通过免疫染色在该基质中证实了I型胶原的定位。超微结构上，环形基质由交织的胶原纤维组成，在其上可辨别出D带周期模式。免疫电子显微镜显示这些纤维上存在I型胶原的免疫反应性。这些结果表明，一些BMP诱导的肥大软骨细胞在其陷窝被侵蚀之前保持其活性并产生富含I型胶原的基质。
