大鼠松质骨中降钙素基因相关肽在脊髓损伤后的变化

背景:细胞因子异常及神经功能的异常、激素水平的改变均参与了脊髓损伤后骨质疏松的发生,以往对细胞因子及激素改变的研究较多,而对神经异常对骨调节的研究相对较少.目的:课题创新性地应用血生化与免疫组织化学相结合的方法,观察脊髓损伤后大鼠松质骨中神经多肽降钙素基因相关肽的变化,分析其在脊髓损伤后骨质疏松中的意义.设计、时间及地点:随机对照动物实验,于2008-09/12在解放军第四军医大学骨科研究所实验室完成.材料:3月龄SD大鼠48只,体质量为(210±16)g,随机均分为脊髓损伤组与对照组,每组24只.方法:脊髓损伤组于T_(10)处完全横断脊髓;对照组仅行椎板切除术.主要观察指标:术后1,3,6周分批每组随机取8只动物处死.测定血骨特异性碱性磷酸酶、I型胶原氨基末端肽;对股骨髁松质骨行降钙素基因相关肽免疫组织化学染色,结合计算机图像分析系统对降钙素基因相关肽免疫阳性神经的染色强度进行定量分析.结果:脊髓损伤组各时间段血清I型胶原氨基末端肽浓度显著高于对照组(P<0.05或0.01),各时间段血清骨特异性碱性磷酸酶活性低于对照组,但差异无显著性意义(P>0.05).对照组各时间段分布于小梁骨内的降钙素基因相关肽免疫阳性神经呈强阳性,脊髓损伤组降钙素基因相关肽较对照组减弱(P<0.05或0.01).结论:脊髓损伤后松质骨内降钙素基因相关肽的减弱可能与脊髓损伤后骨质疏松的发生有关.

Change of calcitonin gene-related peptide in trabecular bone of rats with spinal cord injury

BACKGROUND: Cytokine abnormality, nerve function abnormality and hormone levels may contribute to osteoporosis occurrence following spinal cord injury (SCI), many papers are about cytokine and hormone, but fewer is related to abnormal nerve function on bone accommodation.OBJECTIVE: To innovatively apply blood biochemistry and immunohistochemistry on the observation of change of calcitonin gene-related peptide distributing in trabecular bone of SCI rats, and to analyze its significance in the osteoporosis. DESIGN, TIME AND SETTING: Randomized control animal trials were performed from September 2008 to December 2008 at the laboratory of Orthopedic Institute in the Fourth Military Medical University of Chinese PLA,MATERIALS: Forty-eight Sprague Dawley rats aged 3 months, weighing (210:1:16) g, were divided into SCI group and control group equally. METHODS: Rats in the SCI group underwent spinal cord transection at the tenth thoracic vertebrae. Control rats underwent laminectomy without any spinal cord lesion. MAIN OUTCOME MEASURES: Each 8 rats were sacrificed at 1, 3, 6 weeks postoperatively. The serum concentrations of bone-specific alkaline phosphotase and serum cross-linked N-telopeptide of type Ⅰ collagen were determined. The stain intensity of calcitonin gene-related peptide in trabacular bone was determined with use of quantitative immunohistochemistry technique and computer image analysis system.RESULTS: The cross-linked N-telopeptida of type Ⅰ collagen significantly increased in SCI group at defferent interval compared with control group (P <0.05 or 0.01 ), serum concentrations of bone-specific alkaline phosphotase was lower than control group,without significant difference (P > 0.05). Immunoreactivity of calcitonin gene-related peptide in trabecular bone was strongly positive in control group, while weakened in SCI group (P < 0.05 or 0.01).CONCLUSION: Reduced calcitonin gene-related peptide in trabecular bone of SCI rats may be related to the occurrence of osteoporosis following SCI.