Action of chondroitinase ABC on epidurally transplanted nucleus pulposus in the rabbit.

Study Design: After autotransplanting the nucleus pulposus into the epidural space of rabbits, chondroitinase ABC was administered, and the effect of chondroitinase ABC was examined.
Objectives: To examine whether chondroitinase ABC accelerates resolution of the nucleus pulposus transplanted into the epidural space.
Summary of Background Data: No previous reports exist on the effect of chondroitinase ABC on the nucleus pulposus in the epidural space.
Methods: In Study 1, autotransplantation of the nucleus pulposus into the epidural space was performed in rabbits. Histologic change was observed. In Study 2, dry weight, deoxyribonucleic acid content, and the amount of glycosaminoglycans of autotransplanted nucleus pulposus were quantified and compared with the respective values in the control group, chondroitinase-ABC-injected group, and phosphate-buffered saline-injected group. In Study 3, granulocytes obtained from the blood of a rabbit treated with chondroitinase ABC or phosphate-buffered saline were added to the nucleus pulposus taken from the same rabbit.
Results: In chondroitinase ABC group, inflammatory cells tended to infiltrate earlier than those in the control group (Study 1). The dry weight of recollected nucleus pulposus in the chondroitinase ABC group was significantly less than in the other groups. Deoxyribonucleic acid content in the nucleus pulposus tended to be larger in the chondroitinase ABC group, although no significant difference in content compared with that in the other groups was found. Regarding the residual glycosaminoglycans in the transplanted nucleus pulposus, the amount of chondroitin sulfate markedly decreased in the chondroitinase ABC group (Study 2). The number of granulocytes infiltrating the nucleus pulposus was distinctly large in the chondroitinase ABC group (Study 3).
Conclusion: Chondroitinase ABC can enhance resolution of the nucleus pulposus in the epidural space.