Hindlimb unloading has a greater effect on cortical compared with cancellous bone in mature female rats

Matthew Allen, Susan A. Bloomfield

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

This study was designed to determine the effects of 28 days of hindlimb unloading (HU) on the mature female rat skeleton. In vivo proximal tibia bone mineral density and geometry of HU and cage control (CC) rats were measured with peripheral quantitative computed tomography (pQCT) on days 0 and 28. Postmortem pQCT, histomorphometry, and mechanical testing were performed on tibiae and femora. After 28 days, HU animals had significantly higher daily food consumption (+39%) and lower serum estradiol levels (-49%, P = 0.079) compared with CC. Proximal tibia bone mineral content and cortical bone area significantly declined over 28 days in HU animals (-4.0 and 4.8%, respectively), whereas total and cancellous bone mineral densities were unchanged. HU animals had lower cortical bone formation rates and mineralizing surface at tibial midshaft, whereas differences in similar properties were not detected in cancellous bone of the distal femur. These results suggest that cortical bone, rather than cancellous bone, is more prominently affected by unloading in skeletally mature retired breeder female rats.

Original languageEnglish (US)
Pages (from-to)642-650
Number of pages9
JournalJournal of Applied Physiology
Volume94
Issue number2
StatePublished - Feb 1 2003
Externally publishedYes

Fingerprint

Hindlimb Suspension
Tibia
Bone Density
Femur
Tomography
Osteogenesis
Skeleton
Estradiol
Cancellous Bone
Food
Serum
Cortical Bone

Keywords

  • Bone mineral density
  • Mechanical properties
  • Peripheral quantitative computed tomography, histomorphometry
  • Simulated microgravity

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Hindlimb unloading has a greater effect on cortical compared with cancellous bone in mature female rats. / Allen, Matthew; Bloomfield, Susan A.

In: Journal of Applied Physiology, Vol. 94, No. 2, 01.02.2003, p. 642-650.

Research output: Contribution to journalArticle

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