催产素干预兔骨质疏松模型骨髓脂肪变化规律的实验研究:MRS动态评估

Experimental Study on Oxytocin-Cheated Osteoporosis Model of Rabbit: Dynamic Evaluation of Bone Marow Changes with Magnetic Resonance Spectroscopy

目的探讨催产素干预兔骨质疏松模型的骨髓脂肪变化规律及其可能机制,阐明磁共振波谱(MRS)动态评估的可行性。方法 40只8月龄雌兔,采用双侧去卵(OVX)法制作骨质疏松模型,随机分为骨质疏松模型组(A组,n=20)及催产素干预组(B组,n=20),后者OVX术后2周皮下注射催产素,持续4周。两组于OVX术后3、6、10、14周(每个时间点5只兔)行左股骨上段MRS扫描,计测骨髓脂肪分数(FF)值;同时,采集兔血清测定雌激素(E)、总钙(Ca)、抗酒石酸酸性磷酸酶(TRAP)、特异性碱性磷酸酶(BALP-B)水平。结果 A、B组实验兔骨髓FF值随时间呈渐进性增高,两组每个时间点分别为(46.20±5.24)%、(64.39±5.53)%、(69.13±6.14)%、(78.14±7.42)%以及(42.8±7.11)%、(52.00±3.77)%、(58.25±3.75)%、(61.5±6.63)%,B组自第6周始FF值低于A组,TRAP自6周起低于A组,BALP-B自10周开始高于A组,差异有统计学意义(P<0.01)。两组雌激素、总钙水平随时间变化均有所降低。结论催产素早期干预骨质疏松模型兔能降低骨髓脂肪的堆积,影响骨质疏松的发展进程,早期可能通过抑制破骨、后期通过促进成骨发生作用,MRS可以对此过程进行动态评估。

Objective To dynamically investigate the regular alteration of bone marrow changes in oxytocin cheated os teoporosis model of rabbit using MR spectroscopy. Methods Forty female New Zeal rabbits （8 month old, skeletally ma ture） were randomly divided into two groups. Group A underwent bilateral overiectomy （OVX）. Group B underwent OVX and subcutaneous injection of oxytocin（OT）. Both groups underwent MR spectroscopy （MRS） of left upper femur. Estro gen,total calsium, serum bone metabolism markers at 3,6,10, and 14 weeks after operation（5 rabbits at each time point for each group） were measured. Results Fat fraction （ FF ） of left upper femur were （ 46. 20 ±5. 24 ） %, （ 64. 39 ± 5.53）%, （69.13 ±6.14）%, （78.14 ±7.42） respectively in group A, （42.8±7.11）%, （52.00 ±3.77）%, （58.25 ± 3.75 ） % , （61.5 ± 6.63 ） % respectively in group B. FF of group B at 6, 10, and 14 weeks after OVX were significantly decreased compared to that of group A （ P 〈 0.01 ） , both of which increased over time. Conclusion MRS may be valua ble to dynamically assess bone marrow changes in OP model of rabbits at early stage. It offers primary animal experiment evidence for early assessment of OT treatment with OP patients.