目的: 研究卵巢组织异体移植对去势模型大鼠骨质疏松的治疗作用及其机制。方法: 将40只SD雌性大鼠随机分为假手术组、去卵巢模型组, 雌激素组和卵巢组织块移植组。采用背部定位切除双侧卵巢, 建立去势大鼠模型。造模的同时, 将同种异体卵巢组织块植入去卵巢大鼠背部肌肉层以建立卵巢移植模型。雌激素组大鼠按雌激素0.06 mg/kg灌胃进行替代治疗3个月, 其他各组均给予等量生理盐水。实验结束后, 称量体重和子宫湿重, 计算子宫重量指数; HE染色光镜观察大鼠阴道上皮细胞和股骨细胞形态; 骨密度仪法检测大鼠全身、股骨和胫骨近端的骨密度; 放射免疫法检测血清雌激素(E2)水平。结果: 与假手术组相比, 模型组大鼠子宫重量指数明显下降(P<0.01); 血清雌激素水平显著降低(P<0.01); 阴道上皮细胞较小, 无角质化; 股骨中的骨小梁数目显著减少, 骨吸收明显, 呈典型的“岛屿状”, 骨髓腔增大, 髓腔中基质细胞极少; 双能 X 线显示, 模型大鼠全身、股骨和胫骨的骨密度均显著减少(P均<0.01); 与模型组相比, 雌激素组和移植组大鼠的子宫重量指数增加明显(P<0.01, P<0.01); 两组大鼠的血清雌激素水平上升显著(P<0.01, P<0.01); 病理切片显示, 雌激素组和移植组大鼠的阴道上皮细胞大多呈角质化; 雌激素组大鼠皮质骨增厚, 骨小梁粗壮, 数量多, 排列较整齐, 骨小梁间距较小, 且骨髓腔缩小, 骨基质细胞明显增多; 移植组大鼠皮质骨面积较大, 骨小梁数量和面积增加明显, 骨小梁间距小, 排列规则, 连接增多, 骨基质细胞分布均匀。结论: 卵巢组织移植可能是通过与靶肌肉组织产生新生血管连接, 不断分泌内源性雌激素, 后者通过结合子宫、阴道和股骨组织中靶受体-雌激素受体, 进而维持子宫和阴道等靶组织的形态与功能, 并抑制骨质组织矿物质的丢失, 从而达到改善或促进雌性大鼠内分泌功能的目的。

Objective: To investigate the therapeutic effect and mechanism of ovary tissue allotransplantation on the osteoporosis of ovariectomized rat model. Methods: 40 female SD rats were randomly divided into four groups: sham operation group, ovariectomized model group, estrogen replacement group and ovary allotransplantation group. The ovariectomized model was built by removing bilateral ovaries from backside. After ovariectomization, allogeneic ovary tissue was implanted to muscular layer of back to build ovary allotransplantation model. The rats of estrogen replacement group were intragastric administrated with 0.06 mg/kg estrogen for three months, while rats of other groups were intragastric administrated with same volume of normal saline (NS). After treatment, the body weight and the wet weight of uterus were weighed to calculate the uterus weight index. Morphology of vaginal epithelial and bone cells stained by HE was observed under light microscope. Moreover, bone mineral density (BMD) of whole body, proximal femur and proximal tibia were measured by dual energy x-ray absorptiometry (DXA). Serum estradiol (E2) was measured by radioimmunoassay. Results: Compared with sham operation group, the uterus weight index of the model group significantly declined(P<0.01). The content of serum estradiol significantly reduced(P<0.01). Vaginal epithelial cells were small and not keratinized. The number of bone trabecula in the femur markedly decreased. Bone absorption was obvious, which was shown as “islands”. Few marrow stromal cells existed in the expanded cavity of bone. Bone mineral density of whole body, femur and tibia of ovariectomized model group reduced significantly(P all <0.01). However, compared with ovariectomized model group, the uterus weight indexes and serum estradiol of the estrogen replacement and ovary allotransplantation group significantly increased(P all<0.01). Pathological sections showed that vaginal epithelial cells of both groups were keratinized mostly. In the estrogen replacement group, cortical bone thickened. Bone trabecula was strong with regular arrangement, large number and small space. The number of marrow stromal cells increased in the reduced cavity of bone. In the ovary allotransplantation group, the area of cortical bone was expanded. Besides increased numbers, the area of bone trabecula was also enlarged and the space reduced obviously. The connections increased and ordered. Marrow stromal cells were well distributed. Conclusions: Transplanted ovary tissue may connect with muscular tissue via angiogenesis and then secrete endogenous estrogen. Estrogen can bind receptors of uterus, vagina and femur to maintain morphology and function of these target organs and inhibit the loss of bone mineral, leading to improvement of endocrine function of rats.