Effects of simvastatin versus alendronate on bone loss and biomechanical property deterioration in ovariec-tomized rats / 医学研究生学报

ABSTRACT

Objective Alendronate is widely used as an anti-osteoporosis agent , while simvastatin , as a lipid-lowering drug , is being considered beneficial for bone formation .The present study aims to compare the effects of simvastatin and alendronate on bone loss in ovariectomized ( OVX) rats. Methods Thirty-two female SD rats were equally randomized into a sham operation , an OVX mod-el, a simvastatin ( OVX +S), and an alendronate ( OVX +A) group.All the rats but those in the sham operation group underwent dual ovariectomy .The animals of the OVX model and OVX +S groups were treated intragastrically with vehicle and simvastatin at 5 mg per kg of the body weight per day , respectively , while those of the OVX+A group injected subcutaneously with alendronate at 70μg per kg of the body weight per week .After 12 weeks of intervention , all the rats were sacrificed for detection of the serum concentrations of PINP and ICTP by ELISA, analysis of bone mineral density and bone histo-morphometry parameters of L 4 vertebrae , determination of the maximum loading and elastic modulus of L 5 vertebrae by compression test. Results The serum concentrations of P1NP and ICTP were significantly lower in the sham operation than in the other three groups (P0.05).Bone histomorphometry showed significantly lower BV /TV in the OVX model than in the sham operation and OVX +A groups ([19.9 ±1.69]%vs [29.03 ±2.59]%and [27.05 ±1.91]%, P<0.05), but markedly higher Tb.Sp in the former than in the latter two groups ([357.33 ±26.55] μm vs [211.17 ±16.56] μm and [252.50 ±19.35] μm, P<0.05).The maximum load and elastic modulus of L5 vertebrae were significantly lower in the OVX model rats than in the other three groups (P <0.05). Conclusion Both simvastatin and alendronate can inhibit bone loss in OVX rats , with comparable effects of preventing the deteriora-tion of biomechanical properties , but the latter is evidently more effective in maintaining bone mineral density .