1，25(OH)2D3对模拟失重大鼠股骨远端松质骨的扫描电镜观察

目的 观察1,25-二羟维生素D3对模拟失重状态下大鼠股骨远端松质骨超微结构的影响.方法 SPF级雄性SD大鼠66只,随机分为自由活动组、悬吊对照组和悬吊实验组,同时悬吊实验组给予1,25-二羟维生素D3皮下注射（0.05 μg/kg·d）,实验期为14 d、28 d.取股骨远端沿冠状面切开,蒸馏水冲洗净骨髓腔,乙醇梯度脱水,表面喷金后利用扫描电镜对大鼠股骨远端松质骨的形态结构进行观察.结果 悬吊对照组与自由活动组比较大鼠骨小梁变细,断裂,数目减少,胶原纤维排列杂乱,微损伤增多;悬吊实验组较悬吊对照组大鼠骨小梁数目增多,胶原纤维排列规整,未见明显微骨折发生,且悬吊14 d实验组较悬吊28 d实验组保持了更好的微结构.结论 1,25-二羟维生素D3能够对模拟失重状态下大鼠股骨远端松质骨的超微结构产生有利影响.

Effect of 1,25-dihydroxyvitamin D3 on cancellous bone of distal femur of rats in simulated weightlessness rats under SEM observation

Objective To observe the 1,25-dihydroxyvitamin D_3 on the change of ultrastructural in distal femoral trabecular in male rats after simulated weightlessness. Methods Sixty six male SD rats were randomly divided into six groups: free control for 14,28 d, tail-suspended for 14,28 d and tail-suspended for 14,28 d were treated with 1,25-dihydroxyvitamin D_3. The experiment lasted 14,28 d. The distal femurs were coronarily sectioned. Subsequently, the bone marrow was carefully rinsed with distilled water and dehydrated in graded ethanol. Coated with gold, trabeculae was observed under scanning electron microscopy. Results In group tail-suspended for 14,28 d, trabecular bone of the femur were manifested with fewness, fragility, disconnection and microcrack as compared with control group. Trabecular bone tail-suspended rats for 14 d and treated with 1,25-dihydroxyvitamin D_3 were much better than those for 28 d. Conclusions 1,25-dihydroxyvitamin D_3 has a positive effect on cancellous bone of distal femur in simulated weightlessness rats.