维甲酸致雌性大鼠骨代谢变化的实验研究

Experimental study of tretinoin-induced metabolic changes in conical bone of female rats

目的：建立维甲酸诱导的雌性成年大鼠骨质疏松模型，以探讨其密质骨代谢变化。方法：采用１６只３月龄雌性ＳＤ大鼠，随机分为对照组和维甲酸模型组，后者连续ｉｇ维甲酸７０ｍｇ．ｋｇ－１．ｄ－１，２１天后处死并取内脏称重，胫骨中段制不脱钙骨片用半自动图象分析仪进行测算和分析。结果：维甲酸组卵巢重量显著减轻，子宫萎缩；胫骨中段总面积无明显变化，但骨髓腔变大，皮质变薄；骨外膜动态指标变化不显著，而内膜面荧光周长百分率、骨形成率与骨吸收均有增高趋势，呈骨高转化型改变，但骨吸收大于骨形成，同时类骨质增多。结论：维甲酸在短期内可引起雌性ＳＤ大鼠密质骨丢失，但同时类骨质增多，提示维甲酸造成骨钙化缺陷。

AIM: To study the metabolic changes in conical bone due to tretinoin-induced osteoporosis in female rats. METHODS: Sixteen Sprague-Dawley (SD)female rats, three months of age, were randomly divided into control and tretinoin group with tretinoin ig 70mg. kg-1. d-1 for three weeks. The tibia shafts were processed undecalcified for quantitive bone histomorphometric analysis. RESULTS:The ovary significantly decreased in weight,compared with control group,and the uterus was atrophic.As compared with control group,the tretinoin group did not induce significant changes in total area of conical bone,but the conical bone area was decereased and the marrow cavity area was increased. On periosteal surface,there were no significant changes between the tretinoin and the control groups. However,on endosteal suface, the tretinoin group was characterized by markedly increased percent labeled perimeter (+253%) and stimulated double labeled formation, compared with the control group. In the tretinoin group osteoid increased not only in perimeter but also in area,and was higher than that in the control group. On the other hand, tretinoin increaced percent eroded perimeter (+36%). CONCLUSION:There is a tendency of conical bone loss induced by tretinoin,but tretinoin markedly increased teoid,suggesting that tretinoin may have effect on bone mineralization defect.