降钙素对骨质疏松大鼠骨密度形态计量学与骨代谢的影响

目的探讨降钙素(密盖息)对骨质疏松大鼠骨密度、骨形态计量学影响以及与血钙、磷、维生素D代谢和生长因子的关系。方法用摘除大鼠双侧卵巢的方式制备骨质疏松模型(OVX),实验动物分为4个组:模型对照组、密盖息治疗组,盐酸雷洛昔芬治疗组,假手术组。应用HOLOGIC第4代双能X线4500W骨密度仪测定大鼠腰椎、股骨上段骨密度值(BMD);以骨形态计量学测股骨骨小梁面积、矿化沉积率;用ELISA法测定血清IGF-1水平和血清25OHVitD浓度以及血淋巴细胞维生素D受体(VDR)含量。结果密盖息治疗组、盐酸雷洛昔芬治疗组均较OVX组腰椎、股骨上段骨密度增高,组间比较差异有显著性(P<0.01)。密盖息治疗组较盐酸雷洛昔芬治疗组股骨上段骨密度增高,两组之间差异有显著性(P<0.01)。密盖息治疗组骨小梁面积明显增加、矿化沉积率增高。密盖息治疗组、盐酸雷洛昔芬治疗组血清IGF-1浓度值、血清25-OHVitD浓度值升高,与OVX组比较差异有显著性(P<0.01)。各组血淋巴细胞VDR含量无明显变化,与OVX组比较差异无显著性(P>0.05)。结论密盖息能够预防腰椎、股骨上段骨密度丢失,使骨小梁面积明显增加、矿化沉积率增高并且血清IGF-1及血清25-OHVitD浓度值升高,但对VDR含量无明显作用。

Effect of Calcitonin on Bone Mineral Density and Morphometric Measurement in Experimental Osteoporotic Rats

Objective To evaluate the therapeutic effect of calcitonin on osteoporosis in ovariectomized rats,and to investigate the association between calcitonin and IGF-1 and vitamin D.Methods 40 female 10-month old SD rats were randomized into 4 groups: sham operation group,ovariectomized(OVX) group,calcitonin(CT) group,Raloxifene hydrochloride group.The experimental model of osteoporosis was established by bilateral ovariectomy.Given CT 60 mg/kg body weight subcutaneous injection for 8 weeks,bone mineral densities of global and the lumber spine and femur neck were measured with Hologic dual energy x-ray bone densitometer in rat.Femur trabecular area,bone mineral deposition were measured by morphometry after the completion of therapy.Serum IGF-1 levels and serum 25OHVitD concentrations and lymphocyte vitamin D receptor contents were determined by ELISA.Results BMD of the lumber spine and femur neck in CT group and Raloxifene group were higher than that in OVX control group(P<0.01).Calcitonin increased trabecular area and bone deposition compared with that in OVX group.The serum IGF-1 and 25-OHVitD concentration in CT group and Raloxifene group were significantly higher than that in OVX control group(P<0.01).Conclusion Our findings indicate that the use of calcitonin demonstrated definite effect on IGF-1 levels and vitamin D metabolism and could be an effective therapy for osteoporosis.