Please use this identifier to cite or link to this item:
|Scopus||Web of Science®||Altmetric|
|Title:||Discordance between bone turnover and bone loss: effects of aging and ovariectomy in the rat|
|Citation:||Journal of Bone and Mineral Research, 1999; 14(8):1442-1448|
|Publisher:||AMER SOC BONE & MINERAL RES|
|Paul A. J. Baldock, Allan G. Need, Robert J. Moore, Timothy C. Durbridge,. Howard A. Morris|
|Abstract:||Mechanical strain maintains bone architecture even under conditions of increased bone turnover such as occurs with ovarian hormone deficiency. The rat distal femur contains two sites that apparently experience different levels of mechanical strain and therefore the rat is a suitable model for investigating such effects. The femoral epiphysis experiences higher strain energy compared with the metaphysis and we report the effects of aging between 7 and 12 months and the postovariectomy effects over the same time period on cancellous bone variables measured at these two sites. Age-related bone loss in sham-operated (Sham) animals occurred in both regions, with a greater fall in the metaphysis than in the epiphysis (trabecular bone volume [BV/TV, %] Mean [SEM] Metaphysis: day 0, 25.9 [2.4]; day 150, 8.8 [1.3]: Epiphysis: day 0, 44.8 [1.7]; day 150, 36.7 [1.4] [p < 0.0001]). With ovariectomy (OVX) there was a 73% reduction in cancellous bone at the metaphysis compared with no specific loss at the epiphysis (BV/TV [%] OVX: Metaphysis: day 150, 2.4 [0.4] [p < 0.01 compared with Sham]: Epiphysis: day 150 29.3 [2.7] [NS]). Osteoblast cell activity and osteoclast surface were increased after ovariectomy in both regions. The mineral apposition rate decreased at 9.5 months of age in both regions (p < 0.0001), independent of ovariectomy, and was coincident with a reduction in trabecular number in the epiphyses of both operative groups and in the metaphysis of the ovary-intact group. These data suggest that local mechanical strain governs bone balance with aging and that architectural changes resulting from age-related bone loss may mirror those following estrogen deficiency but occur via a different cellular mechanism.|
|Keywords:||Epiphyses; Femur; Ovary; Animals; Rats; Rats, Sprague-Dawley; Bone Resorption; Ovariectomy; Aging; Bone Development; Biomechanics; Female|
|Rights:||Copyright © 1999 American Society for Bone and Mineral Research|
|Appears in Collections:||Medicine publications|
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.