Linked Life Data

10352107

Source:http://linkedlifedata.com/resource/pubmed/id/10352107

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1999-7-28
pubmed:abstractText
Bone's functional competence is established and maintained, at least partly, by mechanisms involving appropriate adaptation to mechanical loading. These appear to fail in chickens selectively bred either for maximum egg (Egg-type) or meat (Meat-type) production, which show high rates of fracture and skeletal abnormality, respectively. By measuring several early strain-induced responses in cultured embryonic tibiotarsi from commercially bred (Egg-type and Meat-type) and wild-type (Wild-type) chicks, we have investigated the possibility that these skeletal failures are the product of a compromised ability to respond appropriately to loading-induced mechanical strain. Axial loads engendering peak dynamic (1 Hz) longitudinal strains of between -1300 microepsilon and -1500 microepsilon (for 10 minutes) in vitro in tibiotarsi from the three types of 18-day-old chicks increased periosteal osteoblast glucose 6-phosphate dehydrogenase (G6PD) activity in both Wild-type (26%, p < 0.01) and Egg-type (49%, p < 0.001) chicks in situ, while Meat-type chicks did not show any significant changes (11%). Load-induced increases in medium nitrite accumulation (stable nitric oxide [NO] metabolite) were produced in Egg-type and Wild-type tibiotarsi (82 +/- 12%, p < 0.01; 39 +/- 8%, p < 0.01), respectively. In contrast, loading produced no change in NO release from Meat-type chick tibiotarsi. These changes in NO release correlated with load-related increases in G6PD activity (R2 = 0.98, p < 0.05) in the different chick types. Wild-type and Meat-type tibiotarsal periosteal osteoblasts responded in a biphasic manner to exogenous prostacyclin (PGI2), with maximal stimulation of G6PD activity at 10(-7) M and 10(-6) M PGI2. However, Egg-type chick osteoblasts showed smaller, progressive increases up to 10(-5) M PGI2. These results indicate that early phases of the adaptive response to loading differ in different genetic strains of embryonic chick; that skeletal abnormalities which develop in genetically selected, high growth rate chicks may reflect a compromised ability to respond to load; and that load-induced increases in osteoblastic G6PD activity appear to be closely associated with increased rates of NO release. It is probable that similar genetically related differences in bones' responsiveness to mechanical loading occur in other species.
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
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
980-7
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Bone's early responses to mechanical loading differ in distinct genetic strains of chick: selection for enhanced growth reduces skeletal adaptability.
pubmed:affiliation
Department of Veterinary Basic Sciences, The Royal Veterinary College, University of London, London, United Kingdom.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't