TY - JOUR
T1 - Ovariectomy sensitizes rat cortical bone to whole-body vibration
AU - Rubinacci, Alessandro
AU - Marenzana, Massimo
AU - Cavani, Francesco
AU - Colasante, Federica
AU - Villa, Isabella
AU - Willnecker, Johannes
AU - Moro, Gian Luigi
AU - Spreafico, Luigi Paolo
AU - Ferretti, Marzia
AU - Guidobono, Francesca
AU - Marotti, Gastone
PY - 2008/4
Y1 - 2008/4
N2 - This study was designed to determine the modulatory effect of estrogen on mechanical stimulation in bone. Trabecular and cortical bone compartments of ovariectomized rats exposed to whole-body vibration of different amplitudes were evaluated by peripheral quantitative computed tomographic (pQCT) analysis and histomorphometry and compared to controls not exposed to vibration. Rats underwent whole-body vibration (20 minutes/day, 5 days/week) on a vibration platform for 2 months. The control rats were placed on the platform without vibration for the same time. We divided rats into six groups: a sham control (SHAM); a sham vibrated (SHAM-V) at 30 Hz, 0.6 g; a SHAM-V at 30 Hz, 3g; an ovariectomized control (OVX); an ovariectomized vibrated (OVX-V) at 30 Hz, 0.6 g; and an OVX-V at 30 Hz, 3g. In vivo, pQCT analyses of the tibiae were performed at the start of the experiment and after 4 and 8 weeks. After 8 weeks the tibiae were excised for histomorphometric and for in vitro pQCT analyses. In the SHAM-V group, vibration had no effect upon the different bone parameters. In the OVX-V group, vibration induced a significant increase compared to the OVX group of the cortical and medullary areas (P <0.01) and of the periosteal (P <0.01) and endosteal (P <0.05) perimeters at the 3 g vibration. The strain strength index increased in the OVX-V group significantly (P <0.01) at the higher vibration. The results showed that low-amplitude, high-frequency whole-body vibration is anabolic to bone in OVX animals. The osteogenic potential is limited to the modeling of the bone cortex and depends on the amplitude of the vibration.
AB - This study was designed to determine the modulatory effect of estrogen on mechanical stimulation in bone. Trabecular and cortical bone compartments of ovariectomized rats exposed to whole-body vibration of different amplitudes were evaluated by peripheral quantitative computed tomographic (pQCT) analysis and histomorphometry and compared to controls not exposed to vibration. Rats underwent whole-body vibration (20 minutes/day, 5 days/week) on a vibration platform for 2 months. The control rats were placed on the platform without vibration for the same time. We divided rats into six groups: a sham control (SHAM); a sham vibrated (SHAM-V) at 30 Hz, 0.6 g; a SHAM-V at 30 Hz, 3g; an ovariectomized control (OVX); an ovariectomized vibrated (OVX-V) at 30 Hz, 0.6 g; and an OVX-V at 30 Hz, 3g. In vivo, pQCT analyses of the tibiae were performed at the start of the experiment and after 4 and 8 weeks. After 8 weeks the tibiae were excised for histomorphometric and for in vitro pQCT analyses. In the SHAM-V group, vibration had no effect upon the different bone parameters. In the OVX-V group, vibration induced a significant increase compared to the OVX group of the cortical and medullary areas (P <0.01) and of the periosteal (P <0.01) and endosteal (P <0.05) perimeters at the 3 g vibration. The strain strength index increased in the OVX-V group significantly (P <0.01) at the higher vibration. The results showed that low-amplitude, high-frequency whole-body vibration is anabolic to bone in OVX animals. The osteogenic potential is limited to the modeling of the bone cortex and depends on the amplitude of the vibration.
KW - Bone density technology
KW - Exercise
KW - Mechanical loading
KW - Mechanotransduction
KW - pQCT
UR - http://www.scopus.com/inward/record.url?scp=43049141518&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=43049141518&partnerID=8YFLogxK
U2 - 10.1007/s00223-008-9115-8
DO - 10.1007/s00223-008-9115-8
M3 - Article
C2 - 18379712
AN - SCOPUS:43049141518
VL - 82
SP - 316
EP - 326
JO - Calcified Tissue International
JF - Calcified Tissue International
SN - 0171-967X
IS - 4
ER -