ABSTRACT
[Objective]To study the role of nitric oxide on the degeneration of the cartilage endplate(CEP).[Method]Twenty-four New Zealand rabbits were divided into experiment and control groups.In the experiment group,the model of lumbar CEP degeneration was established by resection of all lumbar supraspinous and interspinous ligaments,excision of parts of zygapophysial joints and detachment of the posterior paravertebral muscles from lumbar vertebraes.Mechanical instability of the lumbar spine could induced the process of CEP degeneration.The X-ray examination of lumbar spine was examined by at 12,24 and 36 weeks with or without operation,respectively.Changes of the ultrastructure of CEP were also observed by scanning electron microscope(SEM) during this process,and the content of IL-1?,IL-6,TNF-? in the CEP were also detected during the periods.[Result]X-ray graph showed that the CEP calcified gradually with time increasing,and those of the experiment groups calcified more obviously than those of the control groups.The SEM showed that collagen fibers became thin,irregular and fissured and the content of proteoglycan decreased severely with the elapse of time.The changes in experiment groups were more obvious than those in control groups.The content of IL-1?,IL-6,TNF-? had a significant difference between the experiment groups and the control groups(P0.05).[Conclusion]It implies that inflammatary cytokin may play an important role in the development and progression of the degeneration of cartilage endplate.