补肾、健脾、活血中药对地塞米松诱导骨质疏松大鼠骨组织TRPV5表达的影响

目的:观察地塞米松诱导的骨质疏松大鼠骨组织新型上皮钙通道( TRPV5)基因和蛋白表达的变化,探讨糖皮质激素性骨质疏松症( GIO)的发病机制,并比较补肾、健脾、活血中药的疗效及其调控作用.方法:Wistar大鼠132只,雌雄各半,随机分为正常组、模型组、补肾组(1.139 g·kg-1)、健脾组(0.945 g·kg-1)、活血组(0.504 g·kg-1)和骨疏康组(2.1 g·kg-1).地塞米松im造模(2.5 mg·kg-1),每周2次,造模及给药连续9周.测定离体股骨骨密度(BMD),生化法测定血清骨代谢指标,实时定量PCR与Western -blot法测定骨组织TRPV5 mRNA和蛋白表达.结果:模空组大鼠BMD明显降低(P＜0.01),血清骨吸收标记物TRAP含量明显升高(P＜0.01),骨组织TRPV5 mRNA与蛋白表达均上升(P＜0.01);补肾中药能明显增加模型大鼠股骨BMD(P ＜0.01),降低大鼠血清TRAP含量(P＜0.01),下调骨组织TRPV5 mRNA与蛋白表达水平(P＜0.01或P＜0.05).结论:补肾中药通过下调骨组织TRPV5 mRNA与蛋白表达而抑制破骨细胞骨吸收,从而起到抗骨质疏松的作用,其疗效优于健脾与活血中药.

Effects of Herbs with Functions of Nourishing-kidney,Strengthening-spleen and Promoting-blood Circulation on Expression of TRPV5 in Bone Tissue of Rats with Dexamethasone-induced Osteoporosis

Objective: To observe gene and protein expression of TRPV5 in bone tissue of rats with dexamethasone induced osteoporosis, and to explain pathogenesis of glucocorticoid-induced osteoporosis(GIO), meawhile to compare the effects of herbs with functions of nourishing-kidney,strengthening-spleen and promoting-blood circulation. Method: One hundrad and thirty two Wistar rats were randomly divided into normal group,model group,nourishing-kidney herb group(1.139 g·kg^-1·d^-1),strengthening-spleen herb group(0.945 g·kg^-1·d^-1), activating-blood herb group(0.504 g·kg^-1·d^-1) and Gushukang group(2.1 g·kg^-1·d^-1). The rat osteoporosis models was replicate byintramuscular injection of dexamethasone (2.5 mg·kg^-1)twice a week, lasted for 9 weeks. The BMD of femur in vitro was detected to determine the bone metabolism marker in serum by biochemical process. The mRNA and protein expression of TRPV5 in bone tissue was detected by real-time quantified PCR and Western blot. Result: The BMD of model group decreased obviously(P<0.01), the content of TRAP in serum increased evidently(P<0.01), mRNA and protein expression of TRPV5 in bone tissue of model group rats increased. In nourishing-kidney herb group, the BMD up-regulated(P<0.01), TRAP down-regulated(P<0.01),and the expression of TRPV5 down-regulated evidently compared with the model group. Conclusion: Nourishing-kidney herbs can inhibit bone resorption of osteoclast through down-regulating mRNA and protein expression of TRPV5 in bone tissue, so have the effect of anti-osteoporosis, which is superior to strengthening-spleen and promoting-blood circulation herbs.