前交叉韧带切断对卵巢切除大鼠股骨远段骨密度和骨组织结构的影响

目的采用大鼠切除双侧卵巢(Ovariectomy,OVX)制作骨质疏松症(Osteoporosis,OP)模型,切断右膝前交叉韧带制作骨性关节炎(Osteoarthritis,OA)模型,同时行双侧卵巢切除和右膝前交叉韧带切断制作OVX+OA模型。通过骨密度测量和骨组织形态计量学方法来研究OP与OA的关系。方法3月龄Sprague-Dawley大鼠50只,分成基础对照组(BL,G1),手术对照组(Sham,G2),双侧卵巢切除组(OVX,G3),G4为单纯OA组,G5为OVX+OA组。每组10只动物。所有的实验动物在处死前10天和4天分别皮下注射盐酸四环素和钙黄绿素行荧光双标记。BL组在实验开始时杀死,其余4组在术后6个月后杀死。取大鼠右股骨。用双能X线骨密度仪(DEXA,NORLANDXR-36)测量股骨整体骨密度(total Bone Mineral Density,tBMD)和远段骨密度(distal BMD,dBMD)。取股骨远段进行硬组织包埋、切片,用半自动图象分析仪分析及松质骨骨形态计量学软件处理。结果OVX组与Sham组比较,dBMD和骨量BV/TV显著减少,提示造模成功。OVX+OA组与OVX组比较,dBMD和骨量BV/TV显著增加,骨形成和骨吸收指标均显著降低。OVX+OA组与OA组比较,dB-MD和骨量BV/TV显著减少,骨形成和骨吸收指标均显著升高。结论在本研究SD大鼠切除双侧卵巢制作OP模型,切断右膝前交叉韧带制作OA模型,饲养6个月,提示在OVX+OA模型的股骨远段部位,骨性关节炎可延缓骨质疏松症的发生。

Effect of Anterior Cruciate Ligament Transection on Femural Distal Bone Mineral Density and Bone Structure in Ovariectomized Rats

Objective To determine the relationship of osteoporosis(OP) and osteoarthritis(OA) using transection of anterior cruciate ligament in ovariectomized(OVX) rats.Methods Fifty 3-month-old female Sprague-Dawley rats were divided into five groups of ten animals of each.The baseline control group(BL) was killed at the beginning of the experiment,at 3 months of age.An ovariectomy was performed in twenty rats and ten rats were subjected to a sham surgery.Bilateral ovariectomized group(OVX).Sham-operating group(Sham).Osteoarthritis was induced by transection of the anterior cruciate ligament of the right knee(OA).There was a bilateral ovariectomized and anterior cruciate ligament transected group(OVX+OA).All the animals were double-labeled with subcutaneous injections of tetracycline and calcein at 10 days and 4 days before killed.All the rats were killed at six months postsurgery.Right femora were removed for the measurement of bone mineral density(BMD) by dual-energy X-ray absorptiometry(DEXA)(Norland XR-36).The distal parts of femora were used for bone histomorphometry.Results 1) The bone mass of the OVX group is significantly lower than that of the Sham group.2) The bone mass of the OVX+OA group is significantly higher than that of the OVX group.3) The bone mass of the OVX+OA group is significantly lower than that of the OA group.Parameters of bone formation and resorption in OVX+OA group were significantly higher than those of the OA group.Conclusion In this animal model(six months),OA retards the development of OP on femoral distal part in OVX rats.