The Effect Of Parathyroid Hormone (1-34) In An Experimental Model Of Osteoarthritis Preceded By Osteoporosis

Objectives The purpose of this study is to explore the protective effect,especially of articular cartilage and subchondral bone,that intervention of Parathyroid hormone(PTH)in an experimental model of osteoarthritis preceded by osteoporosis of SpragueDawley(SD)rats,which induced by Ovariectomy(OVX).Methods Eighteen SPF grade three-month-old SD mouse were adaptive fed to threemonth-old,then were randomly divided into three groups with 6 animals each,namely:Sham group,OVX +NS group and OVX +PTH group;PTH were administrated on OVX+PTH group in a dose of 10μg/kg/day by injection,and the same volume of saline were given to OVX +NS group.All animals were sacrificed at the end point of 12 week of administration,then all knees were harvested.Half of the specimen evaluate OARSI marcoscopic score.Toluidine blue stained sections were assessed in accordance with OARSI histological score.The knees were sent to evaluate bone histomorphometry by Micro-CT.The sections were stained by toluidine blue or performed immunohistochemistry by incubating with primary anti-body of Col-II,MMP-13 respectively.Each group of SD rats were analyzed statistically.Results 1 the results of OARSI macroscopic and histological score indicates that,there is no significance in three groups.2 Bone mineral density(BMD)was significantly increased in specimens of OVX+PTH group compare to OVX+NS group.And BMD in OVX+NS group was significantly decreased compared to Sham.BV/TV were significantly increased in specimens of OVX+PTH group compare to and OVX+NS group.And BV/TV were significantly increased in specimens of OVX+NS group compare to and Sham group.Tb.Th were significantly increased in specimens of OVX+PTH group compare to and OVX+NS group.3 The expression level of Col-II in Sham group was significantly increased compared to OVX+NS group;The expression level of Col-II in OVX+PTH group was not significantly increased to compare to OVX+NS group.The MMP-13 expressed higher in OVX+NS group than Sham group and OVX+PTH.Conclusions 1 OVX stimulate the degenerations of subchondral bone and articular cartilage,which proves that 6-month-old OVX rats are animal model to mimic development of postmenopausal OA.2 gavage for 12 weeks of PTH in dose of 10 μg/kg.d showed protective effect on articular cartilage or subchondral bone in an experimental model of osteoarthritis preceded by osteoporosis of Sprague-Dawley(SD)rats,which induced by Ovariectomy(OVX).