ABSTRACT
<p><b>OBJECTIVE</b>To investigate the possible mechanism of immune response in the resorption of the ruptured intervertebral disc herniation, and the possible mechanism of radix astragali on the resorption of the ruptured disc herniation.</p><p><b>METHODS</b>Twenty-eight male SD (Sprague-dawley) rats were chosen. The rats were randomly divided into 4 groups: the control group, model group, the group treated with radix astragali injection and the group treated whit thymic peptide. The rats were killed and discs were harvested 10 days after treatment. Flow cytometry and HE staining were used for analysis of cells and tissue.</p><p><b>RESULTS</b>Compared with the control group, the proportion of activated T cells (CD4+ and CD8+) and B cells were significantly higher in the two drug-treatment groups.</p><p><b>CONCLUSION</b>Herniated nucleus pulposus attracts activated T and B cells and triggered an immune response. Radix astragali could strengthen the autoimmune response.</p>