rhBMP-2在体内诱导成骨中I，II型胶原及碱性磷酸酶的表达

目的：对rhBMP－2在诱导成骨中CollagenI,II及碱性磷酸酶（ALP）的表达进行研究，方法：将含rhBMP-20.5mg的松质骨载体植入55只BALB／c小鼠的右侧股部股袋内，分别术后3－21d共8个时间点取材，采用免疫组织化学方法对新生骨组织中的I，II型胶原进行检测，对ALP活性进行定量分析，观察rhBMP-2在诱导成骨中CollagenI,II及ALP的表达情况，结果：（1）II型胶原的出现是和成软骨，软骨细胞的出现相伴随的，但是，肥大，变性的软骨细胞并不表达II型胶原，（2）作为成骨细胞成熟标志物的I型胶原，ALP在软骨形成期即有表达，但是随着成骨细胞的出现，骨组织的形成I型胶原仍表现为高表达，而ALP的表达则呈下降趋势，结论：在诱导成骨中rhBMP－2促进了CollagenI,IIey ALP的表达。

Expression of collagen I, II and alkaline phosphatase in osteogenesis by rhBMP-2 in vivo

AIM To study expression of collagen I, II and alkaline phosphatase in osteogenesis by rhBMP 2. METHODS Compositions of rhBMP 2 (0.5 mg) and cancellous bone carrier were implanted in the right thigh pouch of 55 BALB/c mice. In order to investigate expression of collagen I, II and alkaline phosphatase in osteogenesis by rhBMP 2, immunohistochemistry analysis was performed 3, 5, 7, 9, 11, 14, 17 and 21 days after the implantation. Meanwhile, alkaline phosphatase activity was measured 7, 14, 21 days after the implantation. RESULTS 1. The appearance of type II collagen was accompanied by that of chondroblasts and chondrocytes, but hypertrophic and degenerative chondrocytes did not express type II collagen. 2. Type I collagen and ALP, osteoblast differentiation markers, were expressed at the early stage of chondrogenesis, but type I collagen was still expressed at higher level, ALP decreased gradually with the appearance of osteoblasts and osteogenesis. CONCLUSION rhBMP 2 might stimulate expression of collagen I, II and alkaline phosphatase in osteogenesis.