J Appl Physiol., 2003; 94(2): 642-50, PMID: 12391029
Hindlimb unloading has a greater effect on cortical compared with cancellous bone in mature female rats
Allen MR, Bloomfield SA
Department of Health and Kinesiology, Texas A&M University, College Station 77843-4243, USA.
AbstractThis 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.
Produktgruppen: pQCT Knochendichte & -geometrie
Themen: Diagnostik mit Leonardo & pQCT, Grundlagenforschung
Doc-ID: 849, 22.01.2008