目的　研究老年大鼠及在促骨合成药前列腺素E2 (PGE2 )作用下松质骨骨重建和骨建造的形态计量学改变 ,探讨动物骨重建形态学新参数测量方法及其意义。方法　 5 0只 2 0月龄雄性Wistar大鼠随机分成 5组 ,年龄对照组 (基础组、10d和 30d年龄对照组 ) ,PGE2 给药组 (分别 10d和30d给予 3mg kg d处理组 )。用体内双荧光标记 ,不脱钙组织切片 ,粘合线 (cementline)染色 ,骨组织形态计量学方法 ,测定骨重建和骨建造参数。结果　 2 0月龄雄性大鼠胫骨近端松质骨的骨形成表面大多数为骨重建单位 (占 6 3 3% ) ,少部分为骨建造单位 (占 2 6 7% ) ;PGE2 用药后骨重建单位增加 1 5倍 ,骨建造单位增加 4倍 ,比值倒置 ,成骨细胞 10d时明显增多。说明PGE2 通过刺激成骨细胞骨合成而介导骨建造性骨量增加和骨重建性骨量增加 ,并以前者为主。结论　老年雄性大鼠松质骨以骨重建活动为主 ,仍有骨建造活动。PGE2 主要通过刺激成骨细胞骨建造而增加骨量 Objective To investigate the morphometric changes of cancellous bone remodeling and bone construction in aged rats and the prostaglandin E2 (PGE2), and to explore the new measurement methods and significance of the new parameters of the animal bone remodeling morphology. Methods 50 male Wistar rats (20 months old) were randomly divided into 5 groups: control group (basal group, 10d and 30d age group) and PGE2 group (3mg / kg and 30d respectively). Dual-fluorescent labeling in vivo, non-decalcified tissue sections, cementline staining, and bone histomorphometry were used to determine bone remodeling and bone building parameters. Results Most of the bone surface of the proximal tibial cancellous bone in 20-month-old male rats were bone-reconstructed units (63.3%) and a few were bone-built units (26.7%). PGE2 The number of reconstructed units increased 15-fold and that of bone-built units increased 4-fold with the ratio inverted. The number of osteoblasts increased significantly at 10 days. PGE2 mediated bone formation by stimulating osteogenesis and bone remodeling increased bone mass, and the former mainly. Conclusion The cancellous bone in the aged male rats is predominantly bone remodeling and there is still bone building activity. PGE2 increases bone mass mainly by stimulating osteoblast construction