老年大鼠松质骨骨重建的组织形态计量学研究

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：50只20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（cement line）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：20月龄雄性大鼠胫骨近端松质骨的形成表面大多数为骨重建单位（占63．3％），少部分为骨建造单位（占26．7％）；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民导骨建造性骨增加和骨重建性骨量增加，并以前为主。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。

Histomorphometric study on cancellous bone remodeling and modeling of aged male Wistar rats

Objective\ To study cancellous bone remodeling and modeling activity in aged male Wistar rats,and to observe the effect of prostaglandin E\-2 (PGE\-2) on them by bone histomorphometry. Methods\ Fifty 20\|month\|old male Wistar rats were divided into basae l,10\|and 30\|day control groups,and 10\|and 30\|day treated groups with 3 mg/kg/d of PGE\-2.After twice in vivo fluorochrome labeling,undecalcified longitudinal sections were subjected to bone histomorphometry and classification of the contour of the cement line in bone formation sites.The later was used to classify bone formation sites into remodeling and modeling and uncertain units. Results\ 63.3% of bone formation sites were remodeling units in the trabecular surface of aged male Wistar rats,and the remaining were modeling and uncertain units.After treatment with PGE\-2,osteoblasts increased markedly in 10 days;fluorochrome labeling surface and bone mass increased dramatically in 30 days' treatment;remodeling sites increased by 1\^5\|fold and modeling sites increased by 5\|fold in both 10 and 30 days'treatment.Conclusion Remodeling is the dominant activity on trabecular bone surface in aged male rats.PGE\-2 increase bone mass mainly by stimulating bone modeling of osteoblasts.