Objective To observe the changes of serum procollagen type Ⅰ C-terminal propeptide (PICP) , osteocalcin (BGP) , and type Ⅰ collagen cross-linked telopeptide (1CTP) in ovariectomized rats, as well as the expression of osteoprotegerin ( OPG) and the nuclear factor KB receptor activator factor ligand ( RANKL) in bone marrow cells. Methods Sixteen 3-month-old female SD rats were randomly divided into 2 groups; the sham-operated control group (n =8) and the ovariectomized group (n =8). Osteoporosis rat model was established using bilateral ovariectomy. Bone mineral density (BMD) was measured using DXA at the 12th week after the surgery. Serum concentrations of PICP, BGP and ITCP were measured using ELISA method. The expression of OPG and RANKL mRNA in bone marrow cells was measured using qRT-PCR. Results Compared to those in sham group, BMD of the lumbar vertebrae and the femurs in ovariectomized rats decreased significantly at the 12th week after the surgery (P＜0.01). Serum concentrations of PICP, BGP, and ICTP increased significantly (P<0. 01). The expression of RANKL mRNA increased significantly (P ＜ 0. 05 ) , and OPG/RANKL ratio decreased ( P＜ 0.01 ) No significant difference was observed in expression of OPG mRNA ( P > 0. 05 ). Conclusions At the 12th week after ovariectomy, rats show the characteristics of high bone turnover ratio. OPG/RANKL/RANK system imbalance may play an important role in bone metabolism characterized by over-reaction of osteoclasts.%目的 观察去卵巢大鼠血清Ⅰ型原胶原C-端前肽(PICP)、骨钙素(BGP)和Ⅰ型胶原交联羧基末端肽(ICTP)的变化,以及骨髓细胞骨保护素(OPG)和核因子κB受体活化因子配体(RANKL)的基因表达变化.方法 取3月龄雌性SD大鼠16只,随机分2组:假手术对照组(8只)和假手术组(8只).采用双侧卵巢切除术复制骨质疏松大鼠模型.术后12周,应用双能X线吸收仪法(DXA)测骨密度,ELISA法测量血清PICP、BGP及ICTP浓度,qRT-PCR法半定量骨髓细胞OPG和RANKL mRNA表达量.结果 与假手术组比较,大鼠去卵巢12周后腰椎和股骨骨密度下降显著(P＜0.01)；血清PICP、BGP和ICTP含量显著升高(P＜0.01)；骨髓细胞RANKL的mRNA表达量增加(P＜0.05)且OPG/RANKL的比率降低(P＜0.01),而两者OPG的mRNA表达量无显著性差别(P＞0.05).结论 去卵巢12周后的大鼠表现出高骨转换率的特点.OPG/RANKL/RANK系统失衡可能在以破骨细胞功能亢进为特点的骨代谢中起重要作用.
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