Linked Life Data

10875273

Source:http://linkedlifedata.com/resource/pubmed/id/10875273

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2000-7-20
pubmed:abstractText
Insulin-like growth factor I (IGF-I) is an important growth factor for bone, yet the mechanisms that mediate its anabolic activity in the skeleton are poorly understood. To examine the effects of locally produced IGF-I in bone in vivo, we targeted expression IGF-I to osteoblasts of transgenic mice using a human osteocalcin promoter. The IGF-I transgene was expressed in bone osteoblasts in OC-IGF-I transgenic mice at high levels in the absence of any change in serum IGF-I levels, or of total body growth. Bone formation rate at the distal femur in 3-week-old OC-IGF-I transgenic mice was approximately twice that of controls. By 6 weeks, bone mineral density as measured by dual energy x-ray, and quantitative computed tomography was significantly greater in OC-IGF-I transgenic mice compared with controls. Histomorphometric measurements revealed a marked (30%) increase femoral cancellous bone volume in the OC-IGF-I transgenic mice, but no change in the total number of osteoblasts or osteoclasts. Transgenic mice also demonstrated an increase in the osteocyte lacunea occupancy, suggesting that IGF-I may extend the osteocyte life span. We conclude that IGF-I produced locally in bone osteoblasts exerts its anabolic effect primarily by increasing the activity of resident osteoblasts.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
141
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2674-82
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Targeted overexpression of insulin-like growth factor I to osteoblasts of transgenic mice: increased trabecular bone volume without increased osteoblast proliferation.
pubmed:affiliation
Department of Medicine, University of Cincinnati College of Medicine, Ohio 45267, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.