大鼠切除卵巢骨质疏松模型的实验研究

目的 研究雌性大鼠在生长期、成年期及切除卵巢后早、中、晚期的骨骼变化，探讨骨质疏松模型形成的最佳条件及评价方法。方法 SD雌性大鼠随机分为正常组、去卵巢(OVX)后1，2，3月和相应的假手术组(SHAM)。用双能X线吸收法(DEXA)测定骨密度(BMD)和骨矿含量(BMC)，处死后取胫骨近端进行骨组织计量学测量，即骨小梁面积百分率(Tb．Ar％)、骨小梁数目(Tb．N)、骨小梁厚度(Tb．Th)和骨小梁分离度(Tb．Sp)。结果 正常组BMC和Tb．Th随月龄持续增加，BMD和Tb．Ar％、Tb．N在成年期达到峰值，以后逐渐下降；OVX组下降显著，BMD和Tb．Ar％在手术1月后差异有显著性，Tb．N在术后2月差异有显著性；正常组Tb．Sp在生长期逐渐下降，成年后增加，OVX组术后增加显著，术后2月差异有显著性。BMD和Tb.Ar%存在正相关关系。结论 正常雌性大鼠在成年期6月龄达到峰值骨量，为建造骨质疏松模型的最佳时间，去卵巢后短时间(1月)模型即成功。骨组织计量学与BMD均为评价骨胳状况的较好方法。

Osteoporosis Model of the Ovariectomized Rat

Objective To study the changes in bone at different time of ovariectomized rats, explore the performing time and detecting methods of osteoporosis model in rat. Methods Female SD rats randomly divided into the ovariectomized(OVX), and sham-OVX groups, and control group. The bone mineral density(BMD) and bone mineral content(BMC) were measured by Dual-energy X-ray absorptiometry. Pathomorphology and histomorphometry of the tibia, including trabecular area(Ar%), trabecular thickness(Th), trabecular number(N), and trabecular separation(Sp) were observed. Results BMC and Th increased continuously by months. Ar%, N and BMD reached the peak at six months, then decreased. Compared with sham-groups, BMD, Ar% and N of OVX groups were lower at one or two month after operation(P<0 01, P<0 05). The trabecular separation decreased at growth period, but OVX group increased significantly at two month after operation. BMD was significantly positively correlated with Ar%. Conclusion Female SD rats had the peak bone mass at six months which is the best time to perform the rat osteoporosis model, and the model was established in one month after ovariectomized. BMD and bone trabecula histomorphometry are indices for assessment of osteoporosis.;