Pathological differences in osteoprosis following menopause or oophorectomy-Analysis of animal models and in vitro-

(1)22周龄SD大鼠随机分为假手术组（Sham）、去卵巢组（OVX）和去卵巢+雌二醇组（OVX+E_2）。治疗3个月后，用DXA测定腰椎（L）<3-5>、股骨近端（F-P）、股骨干骺端（F-M）、股骨远端（F-D）的骨密度（BMD），并测定治疗前后血骨钙素（OC）和尿脱氧吡啶啉（D-Pyr）的含量。OVX+E_2组L_1<3-5>、F-D、F-P、F-D的骨密度显著高于OVX组，F-M无变化。OVX组<3-5>骨吸收指标%D-Py/Cr显著高于Sham组，OVX+ E_2组显著低于OVX组。在任何组中，%OC（成骨指数）均无显著变化。这些发现 关于我们 表明OVX促进骨吸收，导致富含松质骨部位（L_1<3-5>、F-D和F-P）BMD降低，而富含皮质骨部位（F-M）BMD无变化。补充E_2可抑制OVX引起的骨吸收增加，OVX引起的骨密度降低主要由松质骨补充。(2)如上所述，将8周龄雌性ddy小鼠分成三组。在手术后的选定时间间隔取骨髓细胞样本，并使用细胞表面抗原的单克隆抗体通过流式细胞术进行研究。此外，将骨髓细胞和骨基质细胞系一起培养。OVX后2周，骨髓中B-220阳性有核细胞（前B细胞）的数量显著增加。E_2抑制后，前B细胞的特异性增加恢复到假手术组水平。与去卵巢相反，过量E_2可使正常小鼠骨髓B细胞数量明显减少。在共培养体系中，E_2抑制B细胞的增殖和分化。这些发现表明，极端缺乏E引起的骨髓细胞生成的变化改变了骨代谢，这可能导致BMD降低。少

(1) SD rats (22 weeks old) were divided into a sham group, an OVX group, and an OVX+E_2 group. After 3 months, the bone mineral densities (BMD) of the lumbar vertebrae (L_<3-5>) and the proximal end of the femur (F-P), metaphysis of the femur (F-M), and the distal end of the femur (F-D) were measured with DXA.In addition, the levels of osteocalcin (OC) in blood and deoxypyridinoline (D-Pyr) in urine were meaured before and after treatment. The BMDs of L_<3-5>, F-P,and F-D in the OVX group were significantly lower than those in the sham group, but there was no change in F-M.The BMDs of L_<3-5>, and F-D in the OVX+E_2 group were significantly higher than those in the OVX group, but there was no change in F-M.The %D-Py/Cr ratio, an indicator of bone resorption, was significantly higher in the OVX group than in the sham group and significantly lower in the OVX+E_2 group than in the OVX group. There was no significant change in the %OC,an index of osteogenesis, in any group. Thses findings … More indicate that OVX promotes bone resorption, leading to decreased BMD at sites rich in cancellous bone (L_<3-5>, F-D,and F-P) but no change at sites rich in cortical bone (F-M). E_2 replacement inhibits the OVX-induced increase in bone resorption ; the decreased BMD caused by OVX is supplemented primarily by cancellous bone. (2) 8-week-old, female ddy mice were allocated into three groups as described above. Samples of bone marrow cells were taken at selected intervals after operation and studied by flow cytometry with the use of monoclonal antibodies to cell-surface antigens. In addition, bone marrow cells and a bone stromal cell line were cultured together. Two weeks after OVX,a remarkable increase was noted in number of B-220-positive nucleated cells (pre-B cells) in the bone marrow. This specific increase in pre-B cells was improved to the sham level after E_2 replacment. In contrast to the effects of OVX,the administration of excess E_2 to normal mice resulted in a remarkable decrease in the number of bone marrow B cells. In co-culture systems, E_2 inhibited the proliferation and differentiation of B cells. These findings suggest that changes in myelopoiesis induced by extreme E deficiency altered bone metabolism, which may have led to decreased BMD. Less