Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get two FREE E-Books

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Depression: 21st Century Solutions + The Dark Side of Wheat

Abstract Title:

Higher doses of bisphosphonates further improve bone mass, architecture, and strength but not the tissue material properties in aged rats.

Abstract Source:

Bone. 2009 Nov 26. PMID: 19931661

Abstract Author(s):

Mohammad Shahnazari, Wei Yao, WeiWei Dai, Bob Wang, Sophi S Ionova-Martin, Robert O Ritchie, Daniel Heeren, Andrew J Burghardt, Daniel P Nicolella, Michael G Kimiecik, Nancy E Lane

Article Affiliation:

Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA.

Abstract:

We report the results of a series of experiments designed to determine the effects of ibandronate (Ibn) and risedronate (Ris) on a number of bone quality parameters in aged osteopenic rats to explain how bone material and bone mass may be affected by the dose of bisphosphonates (BP) and contribute to their anti-fracture efficacy. Eighteen-month old female rats underwent either ovariectomy or sham surgery. The ovariectomized (OVX) groups were left untreated for 2 months to develop osteopenia. Treatments started at 20 months of age as follows: sham and OVX control (treated with saline), OVX + risedronate 30 and 90 (30 or 90 mug/kg/dose), and OVX + ibandronate 30 and 90 (30 or 90 mug/kg/dose). The treatments were given monthly for 4 months by subcutaneous injection. At sacrifice at 24 months of age the 4th lumbar vertebra was used for muCT scans (bone mass, architecture, and degree of mineralization of bone, DMB) and histomorphometry, and the 6th lumbar vertebra, tibia, and femur were collected for biomechanical testing to determine bone structural and material strength, cortical fracture toughness, and tissue elastic modulus. The compression testing of the vertebral bodies (LVB6) was simulated using finite-element analysis (FEA) to also estimate the bone structural stiffness. Both Ibn and Ris dose-dependently increased bone mass and improved vertebral bone microarchitecture and mechanical properties compared to OVX control. Estimates of vertebral maximum stress from FEA were correlated with vertebral maximum load (r=0.5, p<0.001) and maximum stress (r=0.4, p<0.005) measured experimentally. Tibial bone bending modulus and cortical strength increased compared to OVX with both BP but no dose-dependent effect was observed. DMB and elastic modulus of trabecular bone were improved with Ibn 30 compared to OVX but were not affected in other BP-treated groups. DMB of tibial cortical bone showed no change with BP treatments. The fracture toughness examined in midshaft femurs did not change with BP even with the higher doses. In summary, the anti-fracture efficacy of BP is largely due to their preservation of bone mass and while the higher doses further improve the bone structural properties do not improve the localized bone material characteristics such as tissue strength, elastic modulus, and cortical toughness.

Study Type : Animal Study
Additional Links

Print Options


Key Research Topics

Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get two FREE E-Books

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Depression: 21st Century Solutions + The Dark Side of Wheat

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2019 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.