Sequential treatment with monofluorophosphate and zoledronic acid in osteoporotic rats

Abstract

Objective Osteoporosis is the consequence of an imbalance in bone remodeling caused by excessive resorption or inappropriate bone formation. This paper proposes a sequential treatment with monofluorophosphate (MFP) and zoledronic acid (Z), together with changes in the calcium content in the diet.

Method Seven-week-old female Sprague Dawley rats were divided into five groups (n = 21 per group): (1) sham-operated rats (Sham); (2) ovariectomized (OVX) rats fed with a normal calcium diet (OVX); (3) OVX rats fed with a normal calcium diet and treated sequentially with monofluorophosphate and zoledronic acid (OVX.G1); (4) OVX rats sequentially fed with a low calcium diet and then a high calcium diet, without treatment (OVX.G2); (5): OVX rats fed with a low calcium diet and then a high calcium diet, treated sequentially with monofluorophosphate and zoledronic acid (OVX.G3).

Results After 150 days, the OVX.G3 group showed a similar bone volume to that of the Sham group due to an increase in trabecular number. Dual X-ray absorptiometry bone analysis showed an increase of 9.8% compared with OVX rats. Additionally, an increase in the fracture load at the cortical bone and higher fracture load, ultimate load and stiffness in the compression test were found.

Conclusion The sequential treatment with monofluorophosphate and zoledronic acid increases trabecular bone mass, bone mineral density and bone strength.

Key words::

• MONOFLUOROPHOSPHATE
• ZOLEDRONIC ACID
• OSTEOPOROSIS
• BONE MASS
• BONE STRENGTH

ACKNOWLEDGEMENTS

We thank H. Moreno, D. Vicente, B. Garcia and L. Arias for their technical assistance.

Conflict of interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.

Source of funding This work was funded by grants from National Council of Scientific and Technical Research (CONICET), Argentina (pip 462) and Alberto J. Roemmers Fundation.