雌激素及雄激素对去睾丸大鼠骨质疏松形成的干预研究

Intervention of estrogen and androgen in osteoporosis formation o f orchidectomized rats

目的 研究雌、雄激素对去睾丸大鼠腰椎、股骨颈、粗隆部、股骨近端的骨密度及股骨颈骨微结构的变化。方法 选用 39只 3～ 4月龄的Wistar雄性大鼠 ,随机分成假去睾丸组 (Sham)、去睾丸组 (Orch)、去睾丸 +雌激素组 (Orch +E2 )和去睾丸 +雄激素组 (Orch +T) ,同条件下饲养 1 8w。处死前用HologicQDR 2 0 0 0 +DEXA测量大鼠腰椎、股骨颈、粗隆部、股骨近端的骨密度。处死前第 1 4 ,1 3d和第 3 ,2d行骨荧光标记 ,大鼠处死时收集血清行T和E2 放免检测 ,同时取左侧股骨近端行塑料包埋的骨组织切片及组织形态计量学分析。结果 Orch组大鼠 1 8w后腰椎、股骨颈、粗隆部、股骨近端的骨密度均下降 ,与Sham组比较差异有显著性 (P <0 0 1 )。Orch +E2 组大鼠的 4个部位骨密度均最高 ,但与Sham组比较无差异 ,Orch组股骨颈的骨小梁面积百分率和骨小梁数目与Sham组比较均减少 (P<0 0 1 ) ,骨小梁分离度增加 (P <0 0 1 ) ;Orch +E2 和Orch +T组大鼠的各静态参数维持在Sham组水平 ;Orch组的骨荧光标记周长百分率、骨形成率BFR/BS、BFR/BV和BFR/TV均增加 (P <0 0 1 ) ,代表骨吸收的骨小梁面积破骨细胞数和骨小梁周长破骨细胞数均增加 (P <0 0 1 ) ;Orch +E2 和Orch +T组大鼠的各动态参数维持在Sham组水平。结论 ?

Objective To study the changes in bone mineral de nsity (BMD) of lumbar spines, femoral neck, trochanter and proximal femur, and b one microstructure of femoral neck in orchidectomized rats with estrogen-and a ndr ogen-osteoporosis Methods 39 male Wistar rats, 3 to 4 month s old, were randomly divided into four groups of sham surgery (Sham), orchidectomy (Orch), orchidectomy + estrogen (Orch+E 2) and orchidectomy+ androgen (Orch+T ), and raised 18 weeks under the same conditions BMD in lumbar spine, femoral n eck, trochanter and proximal femur for all rats were determined by Hologic QDR- 2 000+DEXA before sacrifice All animals were Labelled with bone fluorescent reag en ts at 14/13 days and 3/2 days before killing Plasma of all rats were collected to determine concentrations of estradiol and testosterone by radioimunoassay L eft proximal femur stripped off soft tissues was embedded in methyl methacrylate and sectioned, and then bone histomorphometry of the femoral neck was performed Results The BMD in lumbar spine, femoral neck, femoral troc h anter and proximal femur of the Orch group decreased, with statistic ally signif icant difference, compared with the Sham group (P<0 01) The BMD in the s am e parts of the Orch+E 2 group was the highest among the four groups, but not si gnificantly different from that of the Sham group The static parameters, such a s percentage of trabecular area (%Tb Ar), and trabecular number (Tb N), in the O rch group decreased (P<0 01), and trabecular separation (Tb Sp) in the Or ch group increased to that in the Sham group (P<0 01) All static parameter s in the Orch+T and the Orch+E 2 maintained at the same level as that in the Sham The dynamic parameters, such as percentage of labeled perimeter (%L Pm), BFR /B S, BFR/BV and BFR/TV, in the Orch increased to that in the Sham (P<0 01) T he bone resorption parameters, such as osteoclast in trabecular area (Oc No) an d osteoclast in trabecular perimeter (Oc No/Tb Pm), in the Orch increased to th a t in the Sham (P<0 01) All dynamic parameters in the Orch+T and the Orch + E 2 maintained at the same level as those in the Sham Conclusion Estrogen or androgen can restrain the high bone turnover and prevent osteopo rosis in orchidectemized rats Estrogen has an important role in accrual of pea k bone mass and maintaining bone mass in male rats Androgen possibly plays a be tt er role than estrogen in maintaining bone microstructure in orchidectemized rats