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Evidence for reduced cancellous bone mass in the spontaneously hypertensive ratThe histomorphometric changes in the proximal tibial metaphysis and epiphyseal growth plate and midtibial shaft of 26-week-old spontaneously hypertensive rats (SHR) compared with those of the corresponding normotensive Wistar-Kyoto (WKY) rats were studied. A decrease in body weight, growth plate thickness, and longitudinal growth rate of the proximal tibial epiphysis, trabecular bone volume, trabecular thickness and number, the number of osteoblasts and osteoprogenitor cells per millimeter square surface of the proximal tibial metaphysis, periosteal and endocortical apposition rate and bone formation rate of the tibial diaphysis were observed in the SHR. Additionally, systolic blood pressure, the number of osteoclasts per millimeter square surface and average number of nuclei per osteoclast of the proximal tibial metaphysis were significantly increased. Thus, osteoclastic activity is dominant over osteoblastic and chondroblastic activity in the SHR that results in a cancellous bone deficit in the skeleton. It will require additional work to ascertain the underlying cause for this condition as several factors in the SHR with a potential for causing this change are present, including elevated parathyroid hormone (PTH), depressed 1,25-(OH)2D3, low calcium absorption, reduced body weight (reduced loading) elevated blood pressure and possibly other direct cell differences in the mutant strain. At present elevated PTH and adaptation to underloading from reduced weight are postulated to be a likely cause, but additional studies are required to test this interpretation.
Document ID
20050000504
Document Type
Reprint (Version printed in journal)
Authors
Wang, T. M. (Institute of Biology and Anatomy, National Defense Medical Center Taipei, Republic of China)
Hsu, J. F.
Jee, W. S.
Matthews, J. L.
Date Acquired
August 22, 2013
Publication Date
March 1, 1993
Publication Information
Publication: Bone and mineral
Volume: 20
Issue: 3
ISSN: 0169-6009
Subject Category
Aerospace Medicine
Funding Number(s)
CONTRACT_GRANT: AR-38346
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Musculoskeletal
NASA Discipline Number 26-10
NASA Program Space Physiology and Countermeasures
Non-NASA Center