高应力环境导致腰椎软骨终板蛋白聚糖含量改变

The Influence of Abnormal High Mechanical Stress on the Quantitative Changes of Proteoglycan in the Cartilage Endplate in Rats.

采用组织切片的计算机图像分析系技术，测量双后肢大鼠增龄过程中腰椎软骨终板蛋白聚糖（ＰＧ）的含量与分布。８月龄正常大鼠软骨终板外区浅层ＰＧ含量已呈下降趋势，而双后肢大鼠１２月龄组ＰＧ含量开始下降。在此以前，外区浅层ＰＧ含量随年龄增长而加大，尤以双后肢大鼠增加为著，４、８月龄组平均较正常大鼠组增加１７％。１、２月龄双后肢大鼠外区深层和内区ＰＧ含量明显小于对照组，但该差别在４月龄后即不明显。双后肢大鼠软骨终板的过度钙化可能与其ＰＧ含量减少有关。

The authors studied the alteration and distribution of proteoglycan (PG) in the intervertebral cartilage plates of aging bipedal rats with the method of computer image analysis of tissue sections stained with Safranin O, which is bound stoichiometrically to the PG polyanions. In the bipedal rats, the spinal column is naturally subjected to abnormal high mechanical stress. The PG concentration in the superficial layer of the outer zone is gradually increased until to the age of 8 months, especially in the bipedal rats. In 4 and 8 month groups, the bipedal rats had 17% higher PG content than that of the controls (P< 0. 05) . A tendency of decrease of the PG concentration was found in the 8 month old control rats, and in the 12 month age old bipedal rats the PG contents began to decrease. The bipedal rats had a significantly lower PG levels than the normal rat at 1, 2 month in the deep layer and the inner zone of the cartilage plate. This difference was not evident at the age of 4 months. Generally, the PG content of the endplate falls with aging; high stress augments PG content of the superficial layer, however, in the other portion of the cartilage plate the PG contents is reduced. The cartilaginous endplate is considered to play an important role in the nutrition of the nucleus pulposus and hence may be of significance in the etiology of disc degeneration. PG might inhibit the calcification of cartilage, the depletion of PG in the endplate of bipedal rats may be related to its excessive calcification, which could impair the disc nutrition pathway and consequently cause progressive degeneration.