Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1993-4-22
pubmed:abstractText
In adult bone the calcified matrix and enclosed osteocytes are separated from the extracellular space by a continuous layer of bone lining cells. It thus appears that bone matrix is compartmentalised and, as such, may constitute a 'milieu intérieur' which is different from the general extracellular space. Since adult bone matrix is compartmentalised and matrix vesicles also form a microcompartment, it is conceivable that compartmentalisation, in early osteogenesis, may be a requirement for the initial events of the mineralisation process. We have therefore conducted an ultrastructural, tracer, and freeze-fracture study to determine the stage in which bone matrix becomes compartmentalised and also to find out whether there are tight junctions between osteoblasts. The results show that in early nonmineralised stages and in incipient mineralisation, lanthanum penetrates all intercellular spaces and the newly forming bone matrix which is rich in matrix vesicles and collagen. With the progression of mineralisation, when all matrix vesicles appear mineralised and calcification is 'spreading' to the surrounding matrix, lanthanum is restricted to intercellular spaces and conspicuous macular tight junctions are present between osteoblasts. We suggest that matrix vesicles act as microcompartments for calcification when the early bone matrix is in continuity with the surrounding extracellular space. In later stages, when lanthanum fails to penetrate the matrix, matrix vesicles may no longer be necessary because the bone matrix itself is compartmentalised, thus allowing for localised changes in composition that might favour mineral deposition.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-1248646, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-1712792, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-1928750, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-2083087, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-2648065, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-2672881, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-2748621, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-3771650, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-3999181, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-4195919, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-4783420, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-5274475, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-5353625, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-5790994, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-6061727, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-6832908, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-7139726, http://linkedlifedata.com/resource/pubmed/commentcorrection/1295872-912519
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-8782
pubmed:author
pubmed:issnType
Print
pubmed:volume
181 ( Pt 2)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
345-56
pubmed:dateRevised
2010-9-7
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Lanthanum tracer and freeze-fracture studies suggest that compartmentalisation of early bone matrix may be related to initial mineralisation.
pubmed:affiliation
Department of Histology and Embryology, University of São Paulo, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't