骨形态计量学对增龄及去睾丸大鼠骨代谢的实验研究

Bone histomorphometric study of aging male and orchiectomized rats

目的 探讨 3月半龄雄性大鼠增龄及去睾丸后骨量的变化 ,比较两者之间骨代谢的变化。方法 2 0只 3月半龄 SD雄性大鼠 ,随机分成基础对照组、年龄对照组和去睾丸组 ,同等条件下饲养 90天。实验结束 ,取胫骨近端行不脱钙骨制片进行骨组织形态计量学分析。结果 年龄对照组 ( 6月半龄 )与基础对照组 ( 3月半龄 )相比 ,骨组织静态参数骨小梁面积百分率有下降趋势 ,骨的显微结构明显变差 ,动态参数如荧光标记周长百分率、骨形成率和单位骨小梁周长的破骨细胞数等均减少 ,出现骨低转换的改变。去睾丸大鼠与年龄对照组相比 ,静态参数在年龄对照组的基础上进一步减少 (骨小梁面积百分率 -50 % ) ,代表骨吸收和骨形成的动态参数值都明显增加 ,出现骨高转换的改变。结论 增龄的大鼠骨代谢呈低转换 ,有骨量丢失的趋势 ,去睾丸后的大鼠在增龄的基础上呈现骨高转换 ,而骨吸收大于骨形成 。

Objective\ To study the skeletal effects of aging male rats compared with those of orchiectomized(ORX) rats at 90 days after operation and to distinguish the differences between them.Methods\ Twenty 3 and half month old male SD rats were randomly divided into basal control(group A,sacrificed at the beginning),aging control(group B)and orchiectomized(group C)90 days after initiation of the experiment.The proximal tibia(PTM) were processed undecalcified sections of 5 μm and 10 μm in thickness for histomorphometric analysis.Results There were significant changes in aging control group compared with basal control group,including decrease in trabecular bone mass and worse microstructure,resulting in low bone turnover in aging control group.ORX group had decreased trabecular bone mass(-50%)with high bone turnover, compared with matched aging group. Conclusion Ninety day aged and ORX rats have low and high bone turnover respectively,which result in osteoporosis;the both account for the bone loss in ORX 90 day group.