他莫昔芬对去势大鼠松质骨及皮质骨骨密度的影响

目的：选择性雌激素受体调节剂对去势大鼠松质骨，皮质骨骨密度的影响，方法：将21只SD大鼠随机分为3组，每组7只，A组为对照组，B组为去势组，C组为去势＋他莫昔芬组，在去势后5wk给药，术后16wk处死各组大鼠，进行离体骨密度（bone mineral demsity,BMD)测量及组织形态学测量，结果：（1）与对照组相比，去势组去势后16wk股骨头，股骨颈，股骨干，肱骨头，肱骨干，腰椎BND显降低（P＜0．01），骨小梁体积，骨小梁碍度，椎体皮质骨厚度，结连结密度，结密度亦明显降低（P＜0．05）而游离端密度和结连游离瑞密度增高（P＜0．01），（2）他莫昔芬治疗后11wk，各部位BMD增加（P＜0．01），但没有恢复到正常水平（P＜0．05），腰椎骨小梁连接参数恢复到对照组水平（P＞0．05），结论：（1）去势后16wk大鼠松质骨，皮质骨骨量均明显下降，腰椎骨小梁三维结构破坏，骨小梁连结程度降低。（2）他莫昔芬治疗后，松质骨，皮质骨骨量均明显增加，但没有恢复到去势前水平，（3）他莫昔芬能增加腰椎椎体皮质骨厚度，增加腰椎骨小染厚度，增加皮质骨，松质骨骨量，还可提高腰椎微构筑的质量，使骨小染连程度增加。

Influence of tamoxifen on bone mineral density of cancellated bone and compact bone in ovariectomized rats

AIM　To discuss the influence of selective estrogen receptor modulator (SERM) on bone mineral density loss in cancellated bone and compact bone of ovariectomized rats. METHODS　Twenty-one female SD rats were divided into three groups (7 rats per group). Bilateral ovariectomies were done on group B and C. Sham operation was done on group A. Group C was treated with tamoxifen 5 weeks later. Sixteen weeks after operation, all rats were sacrificed. BMD of L1-L5 vertebrae, femoral head, femoral neck, femoral body, humeral head and humeral body were measured by dual energy x-ray absorptiometry (DEXA), and L2 Vertebrae were for histomorphometric analysis. RESULTS　① Sixteen weeks after ovariectomy, BMD of L1-L5 vertebrae, femoral head, femoral neck, femoral body, humeral head, humeral body decreased significantly （P<0.01）, while the density of free endpoints and free-notes struts increased significantly （P<0.01） as compared with sham group. The trabecular became thiner and irregular which changed the bone microstructure in three dimensions. ② After treatment of tamoxifen, the above parameters restored (P<0.05), but not to the level of sham group (P>0.05). CONCLUSION　① Ovariectomy may induce significant decrease of cancellated bone mass and compacts bone mass. ② Treatment tamoxifen could inhibit bone loss, but the bone mass couldn't restore to the level of sham group.