130
· DOS Abstracts
Sheep model reflecting glucocorticoid induced osteo-
porosis in postmenopausal women
Christina Møller Andreasen, Ming Ding, Søren Overgaard, Peter Bollen,
Thomas Levin Andersen
Department of Ortopaedics & Traumatology O, Institute of Clinical Research,
Odense University Hospital, University of Southern Denmark; Department
of Orthopaedics & Traumatology O, Institute of Clinical Research, Odense
University Hospital, University of Southern Denmark; Biomedicine Laboratory,
University of Southern Denmark; Department of Clinical Cell Biology, Institute
of Regional Health Services Research, Vejle-Lillebælt Hospital, University of
Southern Denmark
Background:
Sheep are often used as models for human osteoporosis, but it
has not been verified whether the bone remodelling of sheep is comparable to
human.
Purpose / Aim of Study:
Here we investigate whether the bone loss in gluco-
corticoid treated ovariectomised sheep results from a similar bone remodelling
defect as in osteoporotic postmenopausal women treated with glucocorticoids.
Materials and Methods:
Ten sheep were ovariectomised and treated with
prednisolone for 7 months. Ten untreated sheep served as control. The bone
structure, selected histomorphometric parameters and the serum level of bone
biomarkers were evaluated.
Findings / Results:
Ovariectomy and glucocorticoid treatment induced a sig-
nificant bone loss after 7 months. The extent of bone surfaces colonized by
osteoclasts was unchanged, while the resorption marker CTX had a significant
periodically elevation peaking after one month. The bone formation marker os-
teocalcin was consistently reduced after one week, and the extent of forma-
tive osteoid surfaces was almost undetectable after 7 months. The extent of
reversal surfaces was significant increased after 1 month, covering almost 50%
of the bone surfaces after 7 months. Most of these were arrested reversal sur-
faces without any neighbouring osteoclasts or osteoid surfaces, supporting that
the bone formation and resorption were uncoupled during the reversal phase.
The arrested reversal surfaces had a significantly reduced cell density and im-
munoreactivity for the osteoblastic markers runx2, osterix and SMA.
Conclusions:
In sheep the bone loss results from an uncoupling of the bone
formation and resorption during the reversal phase, as described in osteoporotic
postmenopausal women treated with glucocorticoids, making it a relevant pre-
clinical model for studying orthopaedic implant and biomaterial research under
osteoporotic conditions.
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