1,25(OH)_2D_3对去卵巢大鼠骨组织成骨细胞、骨细胞凋亡的影响

目的观察1,25(OH)_2D_3对去卵巢大鼠骨组织中成骨细胞、骨细胞凋亡的影响。方法 36只雌性SD大鼠随机分成四组,对尼尔雌醇组和1,25(OH)_2D_3组分别给予尼尔雌醇(0.1mg/kg)和1,25(OH)_2D_3(0.05μg/kg)治疗12周。12周后,以DXA法测定大鼠全身的骨密度;放射免疫法测定各组大鼠血清中骨钙素及雌二醇的水平;处死各组大鼠,采用3′-OH末端DNA原位标记技术和透射电镜检测骨细胞、成骨细胞凋亡。结果 12周后,去卵巢组大鼠的骨密度和血清雌二醇水平明显降低,骨钙素含量升高,与假手术组相比,差异有显著性(P0.05)。1,25(OH)_2D_3可以增加去卵巢大鼠的全身骨密度和血清骨钙素含量(P0.05),但是不增加血清雌二醇的水平(P0.05)。1,25(OH)_2D_3可以抑制骨细胞、成骨细胞凋亡,与去卵巢组相比差异有显著性(P0.05)。结论 1,25(OH)_2D_3对去卵巢大鼠骨质疏松症具有防治作用,其部分机制可能为1,25(0H)_2D_3抑制了骨细胞、成骨细胞凋亡,从而调节骨重建。

Effect of 1,25(OH)2D3 on the apoptosis of osteoblast and osteocyte in the bone of ovariectomized rats

Objective To investigate the effect of 1,25 （OH）2 D3 on the apoptosis of osteoblast in the bone of ovariectomized rats. Methods Thirty-six female rats at age of 6 month were allocated into 4 groups with 9 rats per group; ovariectomized （OVX） group, sham-operated group, OVX followed by 1,25 （OH） 2 Ds （ 0. 051μg/kg） and nilestriol （0. lmg/kg） for 12 weeks respectively. Bone mineral density （BMD） of whole body of rats was determined by DXA. The levels of osteocalcin and estradiol in serum were measured by radio immunologic method. All rats were then sacri- ficed, Apoptotic ceils were examined using terminal dexynudeotidyl transferase-mediated dUTP nick end labeling （TUNEL） and apoptotic cells were observed by electron microscope. Results The level of serum E2 and BMD of whole body in the OVX group were lower than those in sham-operated group significantly after 12 weeks （P 〈0. 05）. Compared with the OVX group, the BMD and the level of BGP in the 1,25 （OH）2 D3 group were increased （P 〈 0. 05 ）, but the lev- el of serum E2 was not increased （P 〉 0. 05）. Positive expression rate of apoptotic osteoblasts and osteocytes in the OVX group was higher than that in sham-operated group significantly after 12 weeks （ P 〈 0. 01 ）. Positive expression rate of ap- optotic osteoblasts and osteocytes in 1,25 （OH）2 Ds group was significantly lower than that in OVX group （P 〈 0. 05 ）. Conclusion 1,25 （OH） 2 Ds had antiosteoporotic effects on ovariectomized rats. 1,25 （OH） 2 Ds could inhibit the apopto- sis of osteoblasts and osteoeytes of OVX rats, which might contribute to its antiosteoporotic effect.