Muscone Prevents Endplate Cartilage Degeneration in a Rat Model of the Surgery-induced Cervical Spinal Instability

摘要

Objectives.To study the role of Muscone in the IVD degeneration with the focuses on the vasculature, inflammation and apoptosis in the endplate cartilage.Methods. By excising the paraspinal musculature and posterior cervical spinal ligaments of rats, both static and dynamic cervical forces were disrupted. After surgery, some rats were fed with Muscone. Histopathologic and biochemical features of IVD cells, especially chondrocytes in endplage cartilage, were examined with a series of methods including histology, in situ hybridization for TNF-α, ELISA for IL-1α, PGE2, and 6-keto-prostaglandin F1 alpha (6-K-PGF1α), TUNEL staining, and immunostaining of Fas and bcl-2.Results. Degenerative changes in the rat model of surgery-induced cervical instability were characterized by enhanced local inflammation, and increased apoptosis and decreased blood supply in endplate cartilage. Muscone prevents the degenerative process through several ways. Firstly, it improves blood supply to endplate cartilage as shown by increased number of blood vessles and VEGF expression. Secondly, it significantly suppresses local inflammation as demonstrated by decreased concentration of PGE2, 6-K-PGF1a and IL-1α and downregulated TNF-α expression. Thirdly, it delay the apoptotic process as confirmed by decreased number of the TUNEL positive cells, decreased Fas immunoreactivity and increased immunoreactivity for Bcl-2.Conclusions. Muscone prevents the degenerative changes caused by cervical spine instability by improving blood supply to endplate cartilage, inhibiting local inflammation, and delaying the apoptosis of chondrocyte in endplate cartilage.