卵巢摘除大鼠外周血单核细胞ER-mRNA表达与骨小梁退变的相关研究

Correlation of ER-mRNA expression of peripheral blood monocytes with trabecular bone degenerati on in ovariectomized rats \

目的 探讨外周血单核细胞及其雌激素受体 ( ER) m RNA表达水平 ,在绝经后骨质疏松发生机理中所起的作用。方法 成年雌性 SD大鼠 30只 ,随机分 3组 ,去势组 ( OVX组 ) ,假手术组 ( Sham组 ) ,OVX+Premarin组 ( ERT组 )。术后 6周后采各大鼠心脏血 ,分别以 1用放免法测定血清雌二醇 ;2外周血单核细胞计数以及分离培养纯化单核细胞后运用 RT- PCR法检测 ER- m RNA;3各组行骨组织形态计量学测定。结果 1OVX组与 Sham组相比 ,血清 E2 显著下降 ( P<0 .0 1)。外周血单核细胞( PBM)数显著升高 ( P<0 .0 1) ,而 PBM的 ER- m RNA表达显著降低 ( P<0 .0 1) ,骨组织形态计量学检查 OVX组显示骨小梁面积 ,骨小梁宽度 ,皮质骨面积 ,骨小梁游离末端数均明显降低 ( P<0 .0 5) ,而骨小梁表面破骨细胞数 ,骨矿化沉积率 ,骨矿化缘长度及骨小梁间距等都显著增加 ( P<0 .0 5,P<0 .0 1) ,2 ERT组的血清 E2 ,PBM数及其 ER- m RNA与 Sham组相比无显著差异 ( P<0 .0 5) ,骨量及显微结构亦无明显减少和破坏 ( P<0 .0 5) ,但与 OVX组相比 ,则各项指标均有显著差异 ( P<0 .0 5)。结论 1卵巢切除后骨量丢失可能与单核细胞表达 ER量减少 ,使单核细胞向破骨细胞的分化增多 ,而使骨吸收增强有关。 2激素替代治疗可能通过调节单核?

Objective\ To study the role of peripheral blood monocytes in the mechanism of postmenopausal osteoporosis in ovariectomized rats.Methods\ Thirty female SD rats were randomly allocated to three groups.Group 1:ovariectomized (OVX);Group 2:sham\|operated (Sham);Group 3:OVX+premarin (ERT).Six weeks afer operation,all rats were killed by taking blood from the heart.Then we measured the concentration of E 2 in blood by RIA,counted the number of monocytes and measured the level of ER\|mRNA in the monocytes by semiquantitative RT\|PCR. The proximal femurs were embedded undecalcified for histomorphometric analysis. Results\ (1)Compared with Sham group,the concentration of E 2 in blood and the level of ER\|mRNA in monocytes declined significantly in OVX ( P<0 05 ),but the number of peripheral blood monocytes increased ( P<0 05 ).By histomorphometric analysis the trabecular bone volume,mean cortical thickness,the number of free trabecular in OVX decreased ( P<0 05 );however,the number of osteoclasts was higher than that in Sham group ( P<0 05 ).The trabeculae were thin and irregular which changed the bone structure.(2)There were no significant differences in the above parameters between the ERT group and the Sham group.Conclusion \ Ovarian steriods deficiency induces the increase in number of peripheral blood monocytes and the decline of ER\|mRNA expression in monocytes,which is important for the osteoclastogenesis.The change is crucial for the postmenopausal osteoporosis.Menopause causes a high bone turnover and a decline of bone mechanical strength.ERT is able to inhibit bone absorption by modulating the monocytes and its effects through the ER in the monocytes.