Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2002-3-7
pubmed:abstractText
Departing from the premise that it is the large-amplitude signals inherent to intense functional activity that define bone morphology, we propose that it is the far lower magnitude, high-frequency mechanical signals that continually barrage the skeleton during longer term activities such as standing, which regulate skeletal architecture. To examine this hypothesis, we proposed that brief exposure to slight elevations in these endogenous mechanical signals would suffice to increase bone mass in those bones subject to the stimulus. This was tested by exposing the hind limbs of adult female sheep (n = 9) to 20 min/day of low-level (0.3g), high-frequency (30 Hz) mechanical signals, sufficient to induce a peak of approximately 5 microstrain (micro epsilon) in the tibia. Following euthanasia, peripheral quantitative computed tomography (pQCT) was used to segregate the cortical shell from the trabecular envelope of the proximal femur, revealing a 34.2% increase in bone density in the experimental animals as compared with controls (p = 0.01). Histomorphometric examination of the femur supported these density measurements, with bone volume per total volume increasing by 32% (p = 0.04). This density increase was achieved by two separate strategies: trabecular spacing decreased by 36.1% (p = 0.02), whereas trabecular number increased by 45.6% (p = 0.01), indicating the formation of cancellous bone de novo. There were no significant differences in the radii of animals subject to the stimulus, indicating that the adaptive response was local rather than systemic. The anabolic potential of the signal was evident only in trabecular bone, and there were no differences, as measured by any assay, in the cortical bone. These data suggest that subtle mechanical signals generated during predominant activities such as posture may be potent determinants of skeletal morphology. Given that these strain levels are three orders of magnitude below strains that can damage bone tissue, we believe that a noninvasive stimulus based on this sensitivity has potential for treating skeletal complications such as osteoporosis.
pubmed:grant
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
8756-3282
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
445-52
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Mechanical strain, induced noninvasively in the high-frequency domain, is anabolic to cancellous bone, but not cortical bone.
pubmed:affiliation
Musculo-Skeletal Research Laboratory, Department of Biomedical Engineering, State University of New York, Stony Brook, NY 11794-2580, USA. clinton.rubin@sunysb.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.