| Abstract | 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 microg), zoledronic acid (iv, 100 microg) or continuous raloxifene (2 mg/kg, po, 3x/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. |
| Authors | Wei Yao, Zhiqiang Cheng, Kurt J Koester, Joel W Ager, Mehdi Balooch, Aaron Pham, Solomon Chefo, Cheryl Busse, Robert O Ritchie, Nancy E Lane
(Affiliation: Department of Medicine, Aging Center, UC Davis Medical Center, Sacramento, CA 95817, USA.)
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| Journal | Bone
(Bone)
Vol. 41
Issue 5
Pg. 804-12
(Nov 2007)
ISSN: 8756-3282 United States |
| PMID | 17825637
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
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| Chemical References |
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| Topics |
- Age Factors
- Animals
- Bone Resorption
(prevention & control)
- Bone and Bones
(drug effects)
- Calcification, Physiologic
(drug effects)
- Diphosphonates
(administration & dosage, pharmacology)
- Estrogens
(deficiency)
- Female
- Infusions, Intravenous
- Rats
- Rats, Inbred F344
|
