Effects of retinoic acid on induction osteroporosis model rats and preventive effects of Danshengubao / 中国药理学通报

ABSTRACT

Aim To investigate the effects of retinoic acid (RA) on induction osteroporosis model rats andpreventive effects of Danshengubao.Methods 4-month-old female Sprague-Dawley rats were given RA at 70 mg·kg~(-1)·d~(-1) and were given Danshengubao at different doses at the same time.All rats were treated by oral gavaged for 28 days.The static and dynamic parameters in cancellous bone of the fifth lumbar vertebrae (LV5) were examined and the dynamic changes of the tibial shaft (Tx) were observed with histomorphometrical analyses; the forth lumbar vertebrae (LV4) was used to perform the compression test.Results Compared with control group, biomechanical properties of LV4, the static parameters ( total tissue area, trabecular area, trabecular perimeter) and the dynamic parameters of LV5 were significantly decreased in RA group.Compared with control group, bone formation of Tx was decreased in periosteal surfaces but enhanced in endocortical surfaces in RA group.Compared with RA group, the biomechanical properties of LV4 were increased significantly in low and medium dose of Danshengubao groups.Conclusion sRA can decrease the size and the biomechanical properties of LV, but it can not change the percentage trabecular area. The mechanism may be related to the act that RA can inhibit cancellous bone formation, decrease the modeling of cortical bone in periosteal surfaces and enhance the remolding of cortical bone in endocortical surfaces. Danshengubao can improve biomechanics of LV induced by RA in rats.