12周下坡跑对去卵巢大鼠股骨骨髓脂肪组织容量和微血管密度的影响

Effect of 12-Week Downhill running on Femoral Bone Marrow Adipose Tissue Volume and Microvascular Density in Ovariectomized Rats

目的:探讨运动对去卵巢大鼠骨髓脂肪组织容量及微血管密度的影响。方法:15只9周龄雌性SD大鼠随机分为3组:假手术组(SHAM)、去卵巢组(OVX)、去卵巢+运动组(OVX+EX),每组5只,OVX组和OVX+EX组行去卵巢手术,SHAM组只切除卵巢周围少量脂肪组织。OVX+EX大鼠进行12周跑台下坡跑运动,跑速为18 m/min,每天运动时间为45 min,每周5天。12周后,取右侧股骨进行骨密度测定,取左侧股骨远侧干骺端制成石蜡标本,苏木素-伊红染色(HE)用于观察骨髓病理学改变,计算骨髓脂肪组织容量百分比,采用免疫组织化学技术,CD34抗原标记血管内皮细胞,计算骨髓微血管密度(MVD)。结果:与SHAM组相比,OVX组大鼠骨密度显著下降(P<0.05),提示骨质疏松造模成功;股骨干骺端骨髓脂肪组织容量百分比显著增高(P<0.01),骨髓MVD显著降低(P<0.01);OVX+EX组大鼠骨密度、骨髓MVD均高于OVX组(P<0.05),骨髓脂肪组织容量百分比显著低于OVX组(P<0.05)。结论:12周下坡跑运动可以有效抑制大鼠去卵巢后骨密度的下降,降低骨髓脂肪组织容量,提高骨髓微血管密度。

Objective： To investigate the effect of exercise on bone marrow adipose tissue volume and microvascular density in ovariectomized rats. Methods： fifteen 9-week-old female SD rats were randomly divided into 3 groups： sham operation group（SHAM）,ovariectomized group（OVX）,downhill running group（OVX＋EX）,5 rats in each group. The rats of OVX group and OVX＋EX group underwent ovariectomy,however only a small amount of adipose tissue around the ovary was removed in SHAM group. The rats of OVX＋EX group were running downhill on the treadmill for 12 weeks,the running speed was 18m/min for 45 minutes each day,5 days per week. After 12 weeks,bone mineral density（BMD）of the right femur was measured,the left distal femoral metaphysis was made into paraffin specimen which were stained with haematoxylin-eosin（HE）to observe the changes of bone marrow pathology and calculate the percentage of adipose tissue volume. The bone marrow microvascular density（MVD）was examined by means of immunohistochemical staining for CD34 to mark the vascular endothelial cell. Results： Compared with SHAM group,BMD decreased significantly（P〈0.05）,which indicated the establishment of osteoporosis model,the percentage of adipose tissue volume increases significantly（P〈0.01）,and bone marrow MVD decreased significantly（P〈0.01）in OVX group. BMD and bone marrow MVD in the OVX＋EX group were higher than that of OVX group（P〈0.05）,the percentage of adipose tissue volume was lower than that of OVX group（P〈0.05）. Conclusions： 12-week downhill running can inhibit the decline in BMD in ovariectomized rats,and reduce bone marrow adipose tissue volume and increase bone marrow MVD.