Linked Life Data

8079664

Source:http://linkedlifedata.com/resource/pubmed/id/8079664

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1994-10-6
pubmed:abstractText
An attempt was made to establish whether the activation of plasminogen into plasmin is necessary either for the preparatory phases to bone resorption, involving the recruitment of osteoclast precursors, their migration toward mineralized surfaces, and their final differentiation, or for the subsequent osteoclastic resorption phase. 45Ca-labeled fetal (17 day) mouse metatarsals were cultured under conditions in which they pursue their modeling for a few days. In this model, the resorption phase, monitored by the release of 45Ca into the medium, is entirely dependent on the preparatory phases affecting osteoclast precursors. It was, as expected, stimulated by parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D3 and inhibited by calcitonin. PTH also enhanced the activity of tissue-type plasminogen activator (PA) in extracts of metatarsals but not that of urokinase (which is, however, the main PA present in the mouse fetal metatarsal culture model). The resorption processes were not dependent on the presence of plasminogen in the media, even when the rudiments were precultured with tranexamic acid to remove their endogenous plasminogen. Moreover, they were not influenced by inhibitors of plasmin, either the plasma inhibitors alpha 2-antiplasmin, alpha 2-macroglobulin, and alpha 1-antitrypsin, or aprotinin, which was tested under a variety of conditions. Aprotinin also did not influence the resorption (loss of calcium and hydroxyproline) of 19 day fetal mouse calvariae cultured with PTH in a medium devoid of plasminogen. It is concluded that the various steps implicated in the bone resorption processes that occur in the metatarsals and in the calvariae culture models are not dependent on the activity of plasmin. The function of PAs in bone, however, could be exerted through direct proteolysis of extracellular proteins other than plasminogen or be mediated by a molecular structural domain distinct from their catalytic domain.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0884-0431
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
891-902
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Relationship of the plasminogen activator/plasmin cascade to osteoclast invasion and mineral resorption in explanted fetal metatarsal bones.
pubmed:affiliation
Laboratoire de Chimie Physiologique (Connective Tissue Group), Université de Louvain, Bruxelles, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't