Ikeda T, Yamaguchi A, Yokose S, Nagai Y, Yamato H, Nakamura T, Tsurukami H, Tanizawa T, Yoshiki S
Department of Oral Pathology, School of Dentistry, Showa University, Tokyo, Japan.
J Bone Miner Res. 1996 Jun;11(6):780-8. doi: 10.1002/jbmr.5650110609.
Twelve-week-old female rats were ovariectomized (OVX) and compared with sham-operated control rats at 3, 5, 7, 10, 14, 30, and 60 days postoperation with respect to the expression of type I collagen and osteopontin mRNAs, as well as bone structure and the number of osteoclasts. The trabecular number and separation were significantly decreased and increased, respectively, in the metaphyseal trabecular bones of OVX rat femurs. The number of osteoclasts was significantly increased in the same region of OVX rats at 3 and 5 days postoperation. Type I collagen mRNA was expressed in osteoblasts, and osteopontin mRNA was expressed in some osteoclasts, in mononuclear cells on the bone resorption surface, and in osteocytes near the resorption surface. In the metaphyseal trabecular bone, type I collagen and osteopontin mRNA expression levels in individual cells was initially increased in OVX rats from 7 to 10 days postoperation, and this was sustained for 60 days. The number of osteopontin mRNA-expressing osteocytes was also significantly increased at 10 days postoperation, which lasted until 60 days. In the epiphysis, an increase in type I collagen mRNA expression was initially observed in OVX rats at 14 days postoperation, which lasted until 60 days. The number of osteopontin mRNA-expressing osteocytes was virtually identical until 30 days postoperation in the epiphysis. These findings indicated that the biological activities of osteoblasts and osteocytes are stimulated in bones of the OVX rat and that the response for OVX differs between the metaphysis and epiphysis. Furthermore, the number of osteopontin mRNA-expressing osteocytes was increased only in bones that tended to be resorbed after OVX. This indicates that some osteocytes were stimulated to express osteopontin mRNA by estrogen deficiency and suggests that these osteopontin mRNA-expressing osteocytes may be involved in regulation of bone metabolism.
将12周龄雌性大鼠进行卵巢切除（OVX），并在术后3、5、7、10、14、30和60天与假手术对照组大鼠比较I型胶原蛋白和骨桥蛋白mRNA的表达，以及骨结构和破骨细胞数量。OVX大鼠股骨干骺端小梁骨的小梁数量显著减少，小梁间距显著增加。术后3天和5天，OVX大鼠同一区域的破骨细胞数量显著增加。I型胶原蛋白mRNA在成骨细胞中表达，骨桥蛋白mRNA在一些破骨细胞、骨吸收表面的单核细胞以及吸收表面附近的骨细胞中表达。在干骺端小梁骨中，OVX大鼠术后7至10天单个细胞中I型胶原蛋白和骨桥蛋白mRNA表达水平最初升高，并持续60天。术后10天表达骨桥蛋白mRNA的骨细胞数量也显著增加，持续至60天。在骨骺中，OVX大鼠术后14天最初观察到I型胶原蛋白mRNA表达增加，持续至60天。在骨骺中，直到术后30天，表达骨桥蛋白mRNA的骨细胞数量几乎相同。这些发现表明，OVX大鼠骨骼中成骨细胞和骨细胞的生物活性受到刺激，并且干骺端和骨骺对OVX的反应不同。此外，仅在OVX后易于吸收的骨骼中，表达骨桥蛋白mRNA的骨细胞数量增加。这表明一些骨细胞因雌激素缺乏而被刺激表达骨桥蛋白mRNA，并提示这些表达骨桥蛋白mRNA的骨细胞可能参与骨代谢的调节。
