卵巢切除对鼠及异常应力鼠骨密度影响的比较研究

A Comparision Studies of the Influence of Ovariectomy on Bone Mineral Density in the Rats and Abnormal High Mechanical Stress Rats

目的：探讨卵巢切除雌激素缺乏时鼠及异常应力鼠不同部位骨密度的变化规律。材料与方法：３个月龄ＳＤ雌性大鼠６４只，双侧卵巢切除（ＯＶＸ）及行假手术（Ｓｈａｍ－Ｏ）；于术后第１、３、５、７个月各处死８只动物，切取Ｌ１～Ｌ２椎体节段、股骨及胫骨，进行ＢＭＤ（骨矿密度）检测；新生２４～７２小时雌性ＳＤ鼠４８只，建立双后肢大鼠模型，椎体、股骨及胫骨均承受较高的应力。３月龄时再同法分组，术后第２、５、７个月时分别处死动物取上述部位进行ＢＭＤ检测。结果：ＯＶＸ后第１个月椎体ＢＭＤ明显骨丢失（Ｐ＜０．０１），股骨丢失较为缓慢，７个月时方呈现差异（Ｐ＜０．０５）。松质骨区丢失时间提前（Ｐ＜０．０５）。胫骨１个月ＢＭＤ即有差异性（Ｐ＜０．０５），松质骨区则呈持续丢失。结论：鼠ＯＶＸ后ＢＭＤ的丢失速度为腰椎＞胫骨＞股骨；腰椎体＞胫骨上段＞股骨上段。双后肢大鼠组亦呈现同样变化，但腰椎、股骨及胫骨上的应力增加，ＢＭＤ的丢失较缓慢。

Objective: To explore the influence of ovariectomy on bone mineral density(BMD) loss in different anatomic regions in bothrats and bipedal model rats. Methods: Dual-energy X-ray absorptiometry was carried out to determine the bone mineral density in L 1-2 vertebrae, femur, tibia. 64 3-month-old female SD rats were divided into two groups and bilateral ovariectomies and sham-operation were respectively performed in each group. Bipedal model was produced in 48, 72 hour- old female SD rats to sustain the abnormal high mechanical stress. Three months later, the same procedures were also performed in these rats. The rats were sacrificed at different intervals. Results: Compared with Sham- operated control rats, BMD loss in the vertebrae showed an apparently significant differences(P< 0.01) atthe first month in OVX group. However, BMD loss in the femur showedsignificant differences(P< 0.05) until 7 month later. BMD loss in proximal femur was quicker than that in the total femur at the 3rd month(P< 0.05). BMD loss in the tibia be came obvious at the 3rd month(P<0.05).The same changes were also found in the bipedal rats group.However, the abnormal mechanical stress is so high that the speed of BMD losswas slower. Conclusion: The BMD loss at first occurred in the lumbar vertebrae, secondly in the tibia and then in the femur of both experimental groups.