Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-6-11
pubmed:abstractText
Current approved medical treatments for osteoporosis reduce fracture risk to a greater degree than predicted from change in BMD in women with postmenopausal osteoporosis. We hypothesize that bone active agents improve bone strength in osteoporotic bone by altering different material properties of the bone. Eighteen-month-old female Fischer rats were ovariectomized (OVX) or sham-operated and left untreated for 60 days to induce osteopenia before they were treated with single doses of either risedronate (500 microg/kg, IV), zoledronic acid (100 microg/kg, IV), raloxifene (2 mg/kg, PO, three times per week), hPTH(1-34) (25 microg/kg, SC, three times per week), or vehicle (NS; 1 ml/kg, three times per week). Groups of animals were killed after days 60 and 180 of treatment, and either the proximal tibial metaphysis or lumbar vertebral body were studied. Bone volume and architecture were assessed by muCT and histomorphometry. Measurements of bone quality included the degree of bone mineralization (DBM), localized elastic modulus, bone turnover by histomorphometry, compression testing of the LVB, and three-point bending testing of the femur. The trabecular bone volume, DBM, elastic modulus, and compressive bone strength were all significantly lower at day 60 post-OVX (pretreatment, day 0 study) than at baseline. After 60 days of all of the bone active treatments, bone mass and material measurements agent were restored. However, after 180 days of treatment, the OVX + PTH group further increased BV/TV (+30% from day 60, p < 0.05 within group and between groups). In addition, after 180 days of treatment, there was more highly mineralized cortical and trabecular bone and increased cortical bone size and whole bone strength in OVX + PTH compared with other OVX + antiresorptives. Treatment of estrogen-deficient aged rats with either antiresorptive agents or PTH rapidly improved many aspects of bone quality including microarchitecture, bone mineralization, turnover, and bone strength. However, prolonged treatment for 180 days with PTH resulted in additional gains in bone quality and bone strength, suggesting that the maximal gains in bone strength in cortical and trabecular bone sites may require a longer treatment period with PTH.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1523-4681
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
209-20
pubmed:dateRevised
2010-12-3
pubmed:meshHeading
pubmed-meshheading:18847326-Aging, pubmed-meshheading:18847326-Animals, pubmed-meshheading:18847326-Bone Density Conservation Agents, pubmed-meshheading:18847326-Bone Remodeling, pubmed-meshheading:18847326-Bone Resorption, pubmed-meshheading:18847326-Bone and Bones, pubmed-meshheading:18847326-Calcification, Physiologic, pubmed-meshheading:18847326-Disease Models, Animal, pubmed-meshheading:18847326-Elastic Modulus, pubmed-meshheading:18847326-Estrogens, pubmed-meshheading:18847326-Female, pubmed-meshheading:18847326-Lumbar Vertebrae, pubmed-meshheading:18847326-Osteoporosis, pubmed-meshheading:18847326-Ovariectomy, pubmed-meshheading:18847326-Parathyroid Hormone, pubmed-meshheading:18847326-Rats, pubmed-meshheading:18847326-Rats, Inbred F344, pubmed-meshheading:18847326-Reproducibility of Results, pubmed-meshheading:18847326-Tibia, pubmed-meshheading:18847326-Time Factors, pubmed-meshheading:18847326-X-Ray Microtomography
pubmed:year
2009
pubmed:articleTitle
Prolonged treatments with antiresorptive agents and PTH have different effects on bone strength and the degree of mineralization in old estrogen-deficient osteoporotic rats.
pubmed:affiliation
Department of Medicine, Aging Center, UC Davis Medical Center, Sacramento, California 95817, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural