跳跃性应力刺激对大鼠胫骨OPG、RANKL及骨代谢的影响

The Effect of Jumping on Tibial OPG,RANKL and Bone Metabolism in Rats

目的:研究跳跃性应力刺激对大鼠骨组织的影响,探讨骨质破坏发生的分子生物学机制。方法:48只8周龄雄性SD大鼠,随机平均分为跳跃组和对照组,跳跃组按训练周数标记为J2、J4和J6组,相应对照组为C2、C4和C6组。跳跃组按计划进行跳跃运动训练,对照组安静饲养。每隔2周各组分别处死8只,检测血清碱性磷酸酶(ALP)和抗酒石酸酸性磷酸(StrACP),取一侧胫骨制作HE石蜡切片,另一侧胫骨应用RT-PCR法检测OPG、RANKL mRNA表达。结果:(1)与对照组相比,J6组骨胶原纤维和骨膜排列紊乱,骨皮质出现较大程度破坏,空腔增多。(2)3个跳跃组大鼠血清ALP和StrACP浓度均高于其对照组(P<0.05)。(3)J2组大鼠胫骨OPG mRNA表达量显著低于C2组(P<0.05),而J6组OPG mRNA表达显著高于C6组(P<0.01);J6组RANKL mRNA表达量显著高于C6组(P<0.01)。结论:过度跳跃性应力刺激后,大鼠胫骨OPG和RANKL表达增加,参与以骨转换率升高为特征的骨质破坏过程。

objective To investigate effect of jumping on the bone tissue and explore the molecular mechanism of bone destruction in rats. Methods Forty-eight 8-week old SD rats were equally randomized into jumping group and control group,and 8 rats from two groups were killed every two weeks thereafter. Serum alkaline phosphatase （ALP）and anti-tartaric acid acidic phosphoric acid （StrACP）were detected. Tibial morphology was observed by HE paraffin section,and mRNA expression of osteoprotegerin （OPG）and receptor activator of nuclear factor k B ligand （RANKL）by RT-PCR. Results （1）Disordered periosteal collagen fibers,damaged cortical bone, and the increased cavity were seen 6 weeks after jumping as compared with corresponding control group. （2）The serum ALP and StrACP levels from the 2nd to 6th week after jumping were significantly higher than that in the corresponding control group （P 〈 0.05）. （3）The expression of tibial was lower than the corresponding control group （P 〈 0.05）,while OPGmRNA 2 weeks after jumping significantly higher 6 jumping than that in the corresponding control group （P 〈 0.01 ）. The mRNA expression increased significantly 6 weeks after jumping as compared with the corresponding control weeks after of RANKL group （P〈 0.01）.Conclusion 6-week jumping induces the process of bone destruction characterized by increased bone conversion rate in rats.