The establishment of the experimental animal model of joint contracture, and analysis of the marker gene

本研究在实验模型中检查关节和肌肉的变化，以阐明关节挛缩作为废用综合征症状的病理。制作关节挛缩实验动物模型。对9周龄雄性Wister大鼠进行左侧坐骨神经切断术。作为对照的右侧未进行治疗。神经切除术后第30天，大鼠小腿肌肉出现明显萎缩，膝关节屈曲，活动范围减小。用制备的关节挛缩动物模型的关节软骨，采用定量RT-PCR方法对已知的II型胶原蛋白和聚集蛋白基因进行了评价。去神经组与对照组II型胶原蛋白基因表达水平估测值差异无统计学意义。聚合蛋白的基因表达水平在两组间有显著差异。然后我们检查了软骨细胞的数量和软骨层厚度的变化。在实验期间，两组间软骨细胞的平均数量没有增加或减少的趋势。除神经切除后第7、14天外，去神经组关节软骨厚度均较对照组厚。神经切开术后软骨细胞数量及软骨层形态变化不大。此外，我们还研究了MRI对失神经大鼠肌肉萎缩的定量评价。我们尝试用水和肌酸光谱分析来估计肌肉直径和肌肉内部的扩散系数。在去神经组和对照组之间，估计的扩散系数没有显著差异。在神经切除后第8周，去神经组的纤维直径估计比对照组小。这一结果与神经切开术引起肌肉萎缩的事实一致，但差异无统计学意义。失神经组腓肠肌单位体积（体素）肌酸含量明显低于对照组。神经源性关节挛缩的关节软骨中未检测到预测的未知基因。本研究通过对关节挛缩相关组织的全面评估，包括对标记基因的寻找，揭示了关节挛缩发生过程中病理生理学的复杂性。少

This study was to examine a change of joint and muscle in the experimental model in order to elucidate the pathology of joint contracture as a symptom of disuse syndromes. We made experimental animal model of joint contracture. Neurotomy of the left sciatic nerve was performed on the male 9-week-old Wister rats of 9 weeks old. The right side as a control was not treated. A calf muscle of rat developed a remarkable atrophy at 30th day after neurotomy, and the knee joint showed a flexion position with decreased range of motion. With articular cartilage of the prepared animal model of joint contracture we evaluated the known gene of type II collagen and aggrecan by the quantitative RT-PCR. There was no significant difference in the estimated type II collagen gene expression level between the denervated group and control group. The estimated gene expression level of aggrecan revealed a significant difference between the two groups. Then we examined the number of chondrocyte and the change … More of thickness of a cartilage layer. The average number of chondrocyte did not show any tendency of increase nor tendency of decrease between the two groups during the experimental period. As for the thickness of articular cartilage, the denervated group showed thicker than the control group except for 7th and 14th day after neurotomy. The number of chondrocyte and configuration of the cartilage layer revealed little changes after neurotomy. In addition, we investigated quantitative evaluation of muscle atrophy of denervated rat using MRI. We tried to estimate the muscle diameter and diffusion coefficient inside the muscle with using the water and creatine spectral analysis. There was no significant difference in the estimated diffusion coefficient between the denervated and control groups. The estimated fiber diameter of denervated group showed smaller compared with that of the the control group at the 8th week after neurotomy. This result agreed with the fact that the neurotomy caused muscle atrophy, but the difference was not statistically significant. In denervated group, the creatine content of the gastrocnemius muscle per unit volume (voxel) was smaller than that of the control group. We could not detect the unknown gene which was predicted in the articular cartilage of produced neurogenic joint contracture. This study revealed the complexity of pathophysiology in the development of the joint contracture with having evaluated comprehensively the tissues involved in joint contracture including a search of marker gene. Less