去卵巢大鼠骨密度变化与骨髓造血功能改变的关系

本研究探讨去卵巢大鼠不同时段骨密度的改变与骨髓造血功能改变的关系。探讨骨质疏松的发生与造血功能的关联。50只3月龄SD雌性大鼠随机分为去卵巢（OVX）组和假手术（Sham）组，分别在4周、8周、12周、16周和20周处死。取左侧股骨测量骨密度。右侧远端股骨干骺端松质骨甲醛固定，常规制片观察骨髓组织病理改变，集落形成实验观察造血干细胞集落形成能力，酶联免疫吸附试验（ELISA）检测血清造血生成因子粒-巨噬细胞集落刺激因子（GM—CSF）的浓度。结果表明，大鼠去卵巢4周还未出现明显的骨量丢失时，其骨髓组织即出现明显的脂肪组织容量增加，大鼠去卵巢8周、12周、16周和20周，与同时段假手术组比较股骨骨密度显著减低（P〈0．05），同时伴有骨髓造血组织容量减少，脂肪组织容量增高，巨核细胞数目减少，破骨细胞数目和肥大细胞数目显著增加，与假手术组比较均有显著性差异（P〈0．05）。大鼠去卵巢16周后，造血干细胞形成粒-巨噬细胞集落能力明显低于假手术组。大鼠去卵巢12周后，GM—CSF水平明显低于假手术各组（P〈0．05）。结论：去卵巢大鼠骨密度减低的同时存在骨髓造血功能的减低，3月龄SD雌性大鼠去卵巢可以作为造血功能减低的动物模型，有助于临床上诸多造血功能减低的研究。

Relationship between Changes of Bone Mineral Density and Bone Marrow Pathology in Ovariectomized Rats

This study was purposed to investigate the relationship between sequential changes of bone mineral density and bone marrow hematopoiesis in ovariectomized rats, and explore the correlation between the osteoporosis and the hematopoiesis. Fifty female Sprege-Dawley rats aged 3 months were randomly divided into ovariectomized （OVX） and sham operated （Sham） groups, euthanized after 4, 8, 12,16 and 20 weeks respectively. The bone mineral density （BMD） of left femur was measured. The right femur distal metaphysial cancellous bone was fixed in 10% formalin to observe the changes of the bone marrow pathology. The function of hematopoietic stem cells （HSC） was evaluated by colony forming assay. The level of granulocyte macrophage-colony stimulating factor （GM-CSF） was measured by the enzyme linked immunosorbent assay （ELISA）. The results showed that the BMD of femur in OVX 4 week group not descreased significantly as compared with the Sham 4 group, but the volume of adipose tissur significantly increased. The BMD of femur in OVX 8, 12, 16 and 20 weeks descreased significantly as compared with the corresponding Sham groups （ P 〈 0.05 ）. Meanwhile, the volume of hematopoietic tissue decreased and volume of adipose tissue increased, the megakaryocyte number decreased, the number of osteoclasts and mast cells increased in bone marrow section, as compared with sham operated group （P 〈 0.05）. After rats were ovariectomized for 16 weeks, the GM-CSF level was significantly lower than that of Sham group. After rats were ovariectomized for 12 weeks, the GM-CSF level was obviously lower than that of Sham group （ P 〈 0.05 ）. It is concluded that the bone marrow hematopoiesis funtion also decreases when the BMD of ovariectomized rats reduces. The Sprege-Dawley OVX rats aged 3 months can be used as an model to study the hypohemopoiesis.