Abstract: ［Abstract］〓Objective〖HTSS〗〓To investigate the effects of parathyroid hormone（PTH)（134） on the expressions of matrix metalloproteinase1（MMP1） and MMP13 in the intervertebral disc on an ovariectomized(OVX) rat model.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓Thirty female SpragueDawley rats, 3 month of age, were randomly divided into three groups: the shamoperated(Sham) group and two ovariectomized groups treated with vehicle or PTH(134)(30 μg·kg-1·d-1) for twelve weeks. Treatment was started after twelve weeks postOVX and continued for twelve weeks. At the end of experiment, bone mineral density(BMD), histology and immunohistochemistry analysis were performed to all groups.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓Twenty four weeks after OVX, the BMD values of L3 vertebral bodies in the OVX group were significantly decreased, compared with the Sham group(P＜005). The BMD values in the OVX+PTH group were significantly increased， compared with the Sham group and OVX group(P＜005). Immunohistochemistry analysis revealed a significant increase in matrix metalloproteinase(MMP)1 and MMP13 expression, compared with the Sham group(P＜005), the expression of MMP1 was significantly decreased(P＜005), and no significant difference in MMP13 expression in the OVX+PTH group(P＞005), compared with the OVX group.
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓PTH(134) treatment was effective in reducing the expression of MMP1 and MMP13 in the degenerated disc in OVX rats.

Key words: intervertebral disc degeneration, parathyroid hormone, rats