TY - JOUR
T1 - The degree of bone mineralization is maintained with single intravenous bisphosphonates in aged estrogen-deficient rats and is a strong predictor of bone strength
AU - Yao, Wei
AU - Cheng, Zhiqiang
AU - Koester, Kurt J.
AU - Ager, Joel W.
AU - Balooch, Mehdi
AU - Pham, Aaron
AU - Chefo, Solomon
AU - Busse, Cheryl
AU - Ritchie, Robert O.
AU - Lane, Nancy E
PY - 2007/11
Y1 - 2007/11
N2 - The treatment of osteoporotic women with bisphosphonates significantly reduces the incidence of bone fractures to a degree greater than can be explained by an increase in bone mineral density. In this study, 18-month Fischer 344 rats were ovariectomized and treated with a single dose of risedronate (intravenous, iv, 500 μg), zoledronic acid (iv, 100 μg) or continuous raloxifene (2 mg/kg, po, 3×/week). High resolution microCT was used to measure lumbar vertebral bone microarchitecture, the degree of bone mineralization (DBM) and the distribution of mineral. Small angle X-ray scattering was used to investigate mineral crystallinity. We found prolonged estrogen deficiency, reduced trabecular bone volume, and increased micro architecture bone compression strength lowered the degree of mineralization. Treatment with resorptive agents (bisphosphonates > raloxifene) prevented the loss of mineralization, trabecular bone volume and bone compression strength. Crystal size was not changed with OVX or with anti-resorptive treatments. In conclusion, in the aged estrogen-deficient rat model, single intravenous doses of two bisphosphonates were effective in maintaining the compressive bone strength for 180 days by reducing bone turnover, and maintaining the DBM to a greater degree than with raloxifene.
AB - The treatment of osteoporotic women with bisphosphonates significantly reduces the incidence of bone fractures to a degree greater than can be explained by an increase in bone mineral density. In this study, 18-month Fischer 344 rats were ovariectomized and treated with a single dose of risedronate (intravenous, iv, 500 μg), zoledronic acid (iv, 100 μg) or continuous raloxifene (2 mg/kg, po, 3×/week). High resolution microCT was used to measure lumbar vertebral bone microarchitecture, the degree of bone mineralization (DBM) and the distribution of mineral. Small angle X-ray scattering was used to investigate mineral crystallinity. We found prolonged estrogen deficiency, reduced trabecular bone volume, and increased micro architecture bone compression strength lowered the degree of mineralization. Treatment with resorptive agents (bisphosphonates > raloxifene) prevented the loss of mineralization, trabecular bone volume and bone compression strength. Crystal size was not changed with OVX or with anti-resorptive treatments. In conclusion, in the aged estrogen-deficient rat model, single intravenous doses of two bisphosphonates were effective in maintaining the compressive bone strength for 180 days by reducing bone turnover, and maintaining the DBM to a greater degree than with raloxifene.
KW - Bone mineralization
KW - Compression strength
KW - Intravenous bisphosphonates
KW - OVX
KW - Rat
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U2 - 10.1016/j.bone.2007.06.021
DO - 10.1016/j.bone.2007.06.021
M3 - Article
C2 - 17825637
AN - SCOPUS:35348820573
VL - 41
SP - 804
EP - 812
JO - Bone
JF - Bone
SN - 8756-3282
IS - 5
ER -