Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-10-19
pubmed:abstractText
Bone loss occurs as a consequence of exposure to microgravity. Using the hindlimb-unloaded rat to model spaceflight, this study had as its purpose to determine whether skeletal unloading and cephalic fluid shifts alter bone blood flow. We hypothesized that perfusion would be diminished in the hindlimb bones and increased in skeletal structures of the forelimbs and head. Using radiolabeled microspheres, we measured skeletal perfusion during control standing and after 10 min, 7 days, and 28 days of hindlimb unloading (HU). Femoral and tibial perfusion were reduced with 10 min of HU, and blood flow to the femoral shaft and marrow were further diminished with 28 days of HU. Correspondingly, the mass of femora (-11%, P < 0. 05) and tibiae (-6%, P < 0.1) was lowered with 28 days of HU. In contrast, blood flow to the skull, mandible, clavicle, and humerus was increased with 10 min HU but returned to control levels with 7 days HU. Mandibular (+10%, P < 0.05), clavicular (+18%, P < 0.05), and humeral (+8%, P < 0.1) mass was increased with chronic HU. The data demonstrate that simulated microgravity alters bone perfusion and that such alterations correspond to unloading-induced changes in bone mass. These results support the hypothesis that alterations in bone blood flow provide a stimulus for bone remodeling during periods of microgravity.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
89
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1046-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Alterations in skeletal perfusion with simulated microgravity: a possible mechanism for bone remodeling.
pubmed:affiliation
Department of Health and Kinesiology, and Cardiovascular Research Institute, Texas A&M University, College Station, Texas 77843, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.