Kudo T, Sumi A, Hashimoto A
Department of Veterinary Surgery, Faculty of Agriculture, Gifu University, Japan.
J Vet Med Sci. 1993 Apr;55(2):211-5. doi: 10.1292/jvms.55.211.
The present study describes the radiological and histological changes in the canine intervertebral disk after the experimental injection of chymopapain as the chemical reagent, and determines the appropriate dose of the enzyme for treatment of herniated disks. By radiography, narrowing of the disk space was observed within 2 weeks after the injection of chymopapain, and recovered to 74.1% in the 0.1 mg group, 61.1% in the 1.0 mg group and 71.7% in the 10.0 mg group at 12 weeks. The disk space recovery showed a tendency to delay with aging. Microscopically, proteoglycan positive matrix appeared and the nuclear space was reduced in each disk at 2 weeks after chymopapain injection. The nucleus pulposus contained an irregularly-defined mass consisting of clusters of degenerated notochordal cells surrounded by proliferated chondrocytes and collagen matrix. In each disk at 12 weeks after chymopapain injection, the center of the nucleus pulposus was replaced by fibrocartilage tissue. In the disk into which 10.0 mg chymopapain was injected, the nuclear space filled with dense fibrocartilage tissue without a regenerated matrix component and narrowing of the disk were maintained. It is suggested that canine chemonucleolysis with 10.0 mg of chymopapain reduces the interdiskal pressure. This treatment may therefore relieve the signs and symptoms of herniation of the nucleus pulposus, and may effect chemical disk decompression.
本研究描述了实验性注射木瓜凝乳蛋白酶作为化学试剂后犬椎间盘的放射学和组织学变化，并确定了用于治疗椎间盘突出症的酶的合适剂量。通过放射学检查，注射木瓜凝乳蛋白酶后2周内观察到椎间盘间隙变窄，在12周时，0.1mg组恢复到74.1%，1.0mg组恢复到61.1%，10.0mg组恢复到71.7%。椎间盘间隙的恢复呈现出随年龄增长而延迟的趋势。显微镜下，注射木瓜凝乳蛋白酶后2周，每个椎间盘出现蛋白聚糖阳性基质，核间隙减小。髓核包含一个不规则定义的团块，由退化的脊索细胞簇组成，周围是增殖的软骨细胞和胶原基质。注射木瓜凝乳蛋白酶后12周，每个椎间盘的髓核中心被纤维软骨组织取代。在注射10.0mg木瓜凝乳蛋白酶的椎间盘中，充满致密纤维软骨组织的核间隙没有再生的基质成分，并且椎间盘间隙变窄得以维持。提示用10.0mg木瓜凝乳蛋白酶进行犬化学髓核溶解术可降低椎间盘间压力。因此，这种治疗可能缓解髓核突出的体征和症状，并可能实现化学性椎间盘减压。
