Protective effect of calcitonin on lumbar fusion-induced adjacent-segment disc degeneration in ovariectomized rat.
BMC Musculoskelet Disord. 2015;16(1):342
Authors: Liu CC, Tian FM, Zhou Z, Wang P, Gou Y, Zhang H, Wang WY, Shen Y, Zhang YZ, Zhang L
BACKGROUND: Intervertebral disc (IVD) degeneration and pathological changes in the spinal cord are major causes of back pain. In addition to its well-established anti-resorptive effect on bone, calcitonin (CT) potentially exerts protective effects on IVD degeneration in ovariectomized rats. However, possible therapeutic effects of CT on lumbar fusion-induced adjacent-segment disc degeneration (ASDD) have not been investigated yet. In this study, we examined the effects of CT on IVD degeneration adjacent to a lumbar fusion in ovariectomized rats.
METHODS: Posterolateral lumbar fusion (PLF) at L4-5 was performed 4 weeks after ovariectomy (OVX) or sham surgery in female Sprague-Dawley rats. Following PLF?+?OVX, rats received either salmon CT (OVX?+?PLF?+?sCT, 16 IU/Kg/2d) or vehicle (OVX?+?PLF?+?V) treatment for 12 weeks; the remaining rats were divided into Sham?+?V, OVX?+?V, and PLF?+?V groups. Fusion status was analyzed by manual palpation and radiography. Adjacent segment disc was assessed by histological, histomorphometric, immunohistochemical analysis. L6 vertebrae microstructures were evaluated by micro-computed tomography.
RESULTS: Histological analysis showed more severe ASDD occurred in OVX?+?PLF?+?V rats compared with the OVX?+?V or PLF?+?V groups. CT treatment suppressed the score for ASDD, increased disc height, and decreased the area of endplate calcification. Immunohistochemical staining demonstrated that CT decreased the expression of collagen type-I, matrix metalloproteinase-13, and a disintegrin and metalloproteinase with thrombospondin motifs-4, whereas it increased the expression of collagen type-II and aggrecan in the disc. Micro-computed tomography indicated that CT increased bone mass and improved the microstructure of the L6 vertebrae.
CONCLUSIONS: These results suggest that CT can prevent ASDD, induce beneficial changes in IVD metabolism, and inhibit deterioration of the trabecular microarchitecture of vertebrae in osteoporotic rats with lumbar fusion.
PMID: 26552386 [PubMed – in process]