The RANK/ RANKL/ OPG interaction in the repair of autogenous bone grafts in female rats with estrogen deficiency

The aim of this study was to evaluate the resorption process during the repair of autogenous bone grafts with or without coverage by an expanded polytetrafluoroethylene (e-PTFE) membrane in female rats with estrogen deficiency using the immunohistochemical technique. Eighty female rats were randomly divided into two groups (OVX and SHAM). The 40 female rats in the OVX group were subjected to ovariectomy, and the 40 female rats in the SHAM group were subjected to simulated ovariectomy. The two groups were further divided in subgroup E, which was subjected to surgery for placement of autogenous bone graft (ABG), and subgroup ME, in which the ABG was covered with an e-PTFE membrane. The animals were killed at 0, 7, 21, 45 and 60 days. The specimens were analyzed using immunohistochemistry for the bone resorption markers RANK, RANK-L and Osteoprotegerin (OPG). A higher remodeling rate was observed at 7 and 21 days after the autogenous bone grafts, when the markers were more intensely expressed. At the final time point, the specimens presented similar characteristics to those observed at the initial time point. The expression of immunohistochemical markers was not altered by the estrogen deficiency. The presence of the e-PTFE membrane delayed the bone resorption process, influencing the immunohistochemical expression of markers.

本研究旨在通过免疫组织化学技术，评估雌激素缺乏雌性大鼠自体骨移植物（autogenous bone graft, ABG）伴或不伴膨体聚四氟乙烯（expanded polytetrafluoroethylene, e-PTFE）膜覆盖修复过程中的骨吸收进程。将80只雌性大鼠随机分为两组：去卵巢组（OVX）与假手术组（SHAM），每组各40只。其中去卵巢组大鼠接受卵巢切除术，假手术组大鼠接受模拟卵巢切除术。两组再进一步划分为两个亚组：亚组E仅植入自体骨移植物，亚组ME则在自体骨移植物表面覆盖e-PTFE膜。分别于术后0、7、21、45及60天处死各组大鼠。采用免疫组织化学法检测骨吸收标志物RANK、RANK-L及骨保护素（Osteoprotegerin, OPG）以分析标本。结果显示，自体骨移植后7天与21天，骨重塑速率更高，此时相关标志物的表达更为强烈；至实验最终时间点，标本特征与初始时间点相似。雌激素缺乏并未改变免疫组化标志物的表达水平。此外，e-PTFE膜的存在可延缓骨吸收进程，对标志物的免疫组织化学表达产生影响。