Abstract: 〗［Abstract］ Objective〖HTSS〗〓To investigate the effects of parathyroid hormone（PTH)（134） on the expressions of type Ⅰ collagen and type Ⅹ collagen in the cartilage endplate on  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, histology and immunohistochemistry analysis were performed to all groups.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓 The cartilage endplate in the Sham group appeared normal. In the OVX group, the cartilage endplate showed degenerative changes, where the bony tissues that contained bone marrow, hematopoietic lineage cells and mineralized bone, became more obvious. In contrast, the histological morphology in the OVX + PTH group showed a fewer bony tissues formed in the cartilage endplate. The results of molecular analysis revealed a significant increase in type Ⅰ collagen and type Ⅹ collagen expressions in the OVX group than that in the Sham group(P＜005), and marked reductions in the type Ⅰ collagen and type Ⅹ collagen expressions in the OVX+PTH group than that in the OVX group(P＜005).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓PTH(134) treatment was effective in reducing the expression of type Ⅰ collagen and type Ⅹ collagen in the cartilage endplate in OVX rats.

Key words: intervertebral disc, cartilage endplate, collagen type Ⅰ, collagen type Ⅹ, parathyroid hormone