去卵巢大鼠骨密度变化与骨髓组织血管生成的关系

Relationship between changes of bone mineral density and bone marrow angiogenesis in ovariectomized rats

目的:探讨去卵巢大鼠骨密度变化与骨髓组织血管生成的关系。方法:30只SD雌性大鼠随机分为去卵巢组(OVX)和假手术组(sham),分别在4周、8周和12周处死。取左侧股骨测量骨密度(BMD)。右侧远端股骨干骺端松质骨甲醛固定,EDTA-Na2脱钙。常规脱水、石蜡包埋、切片。行苏木素-伊红染色用于观察骨髓组织病理改变,用CD34标记血管内皮细胞观察微血管密度(MVD),采取大鼠腹主动脉血进行血管内皮生长因子(VEGF)测定。结果:大鼠去卵巢8周后BMD明显低于假手术组,提示骨质疏松模型建立,此时,骨髓造血组织容量减少,脂肪组织容量增高,与假手术组比较均有显著差异(P<0.01),骨髓组织MVD与假手术组比略有减少。12周后,上述改变更为明显。同时,骨小梁容量减少,骨髓组织MVD明显减少(P<0.05),且显示MVD与BMD、造血组织容量和骨小梁容量呈正相关,与脂肪组织容量呈负相关。但血浆VEGF含量测定OVX组与sham组间无明显差异,与骨髓组织各形态指标亦无相关性。结论:去卵巢大鼠在骨量丢失和造血组织容量减少的同时伴有骨髓组织MVD减少,为骨质疏松症采用促微血管增生治疗提供了实验依据。

AIM： To explore the relationship between the changes of bone mineral density （BMD） and bone marrow angiogenesis in ovariectomized rats. METHODS： Thirty female Sprague -Dawley rats （3 month -age） were ran- domly divided into ovariectomized （OVX） groups and sham operated （sham） groups, and executed after 4 weeks, 8 weeks and 12 weeks respectively. The bone mineral density （BMD） of left femora was measured. The right distal femoral epiphysis was fixed in formalin, decalcificated by EDTA - Na2, dehydrated and embedded in paraffin. Four - μm - thick slices were obtained from the paraffin section and stained with haematoxylin - eosin （HE） for bone marrow pathological examination. The number of bone marrow microvessels was examined by means of immunohistochemical staining for CD34 to stain the endothelial cells of blood vessels to definite the bone marrow microvascular density （MVD）. Plasma levels of vascular endothelial growth factor （VEGF） were examined by the method of ELISA. RESULTS： The BMD of femoral in 8 -week OVX group were decreased significantly compared to the 8 - week sham group （ P 〈 0. 05 ）, suggesting the establishment of osteoporosis model. Meanwhile, the area of hematopoietic tissue decreased and the area of adipose tissue increased. These changes became obviously in 12 - week OVX group, and the area of trabecular bone and the bone marrow MVD significantly decreased compared to the 12 -week sham group. A positive correlation between MVD and BMD, area of hematopoietic or trabecular bone as well as a negative correlation between MVD and area of adipose tissue were observed. The plasma levels of VEGF in OVX group were not significantly different from that in sham group, and had no correlation relationship with the indexes of bone marrow pathology. CONCLUSION ： There has an increase in MVD companied with the bone mass loss and hematopoietic tissue decreased in ovarietomized rats, which provide experiment proof to treat osteoporosis with the means of promoting of MVD in bone marrow.