A discogenic pain rat model induced by percutaneous puncture annulus / 中国组织工程研究

ABSTRACT

BACKGROUND:There are many animal models used for studying discogenic pain, but percutaneous puncture annulus is rarely reported. Minimal y invasive approach to establish a discogenic pain model in Spraque-Dawley rats could reduce the interference factors of surgical trauma. OBJECTIVE:To establish a Spraque-Dawley rat model of discogenic pain by percutaneous puncture annulus, with easy operations, high stability and obtaining large-scale productions, and to confirm the model by the results of behavior, MRI and molecular biology. METHODS:Eighty-eight male Sprague-Dawley rats, of specific pathogen free level, were randomly divided into three groups, model group (n=44), control group (n=10) and sham group (n=34). In the model group, the annulus was percutaneously punctured under X-ray guidance;while rats in the sham group were punctured at the paravertebral tissue, rather than the annulus. RESULTS AND CONCLUSION:The 50%mechanical withdrawal threshold of both hind paws in model group were reduced compared with control group and sham group. In the model group, the L 5/6 intervertebral disc degeneration was apparently visible, and the degree of degeneration was aggravated along the time. In the model group, the expression of calcitonin gene-related peptide in dorsal root ganglion of rats began to increase at 3 days post-operation and reached the peak at 21 days post-operation, then remained at high levels until the 35th day post-operation. The expression of tumor necrosis factor-αin dorsal root ganglion of rats increased at 3 days post-operation and reached the peak at 14 days post-operation, then remained at a higher level until the 35th day post-operation. The experiment result verifies that the discogenic pain model of Spraque-Dawley rats induced by percutaneous puncture annulus has the advantages of good stability and less trauma. The model can be used to study discogenic pain.