Abstract
Estrogen deficiency results in a loss of trabecular bone mass and structure that leads to an increased incidence of osteoporotic fractures. The purpose of this study was to determine the time course for trabecular structure deterioration and changes in bone turnover just after ovariectomy in the rat. Six-month-old female virgin Sprague-Dawley rats had their right proximal tibia scanned by X-ray tomographic microscopy (XTM) at baseline (day 0). Animals were then randomized into two groups, and in each group 9 were sham-operated and 11 were ovariectomized and had repeat XTM scans on days 5, 13, 29, and 42 postovariectomy in group 1 and on days 8, 13, 33, and 50 postovariectomy in group 2. Urine was collected for deoxypyridinoline (DPD) cross-link measurements 24 h before each XTM scan and analyzed by ELISA. Trabecular bone structural variables and bone turnover endpoints were calculated from XTM data and standard histomorphometry. Trabecular connectivity decreased 27% by days 5 and 8 postovariectomy (p < 0.01) and continued to decrease up to day 50 postovariectomy (p < 0.01). The trabecular bone volume decreased 25% by 8 days postovariectomy (p < 0.01), and it continued to decrease through day 50. DPD cross-link excretion had increased 37% on day 13 (p < 0.01) and by over 100% of baseline by day 50 postovariectomy. Trabecular bone connectivity and volume deteriorate rapidly while DPD cross-link excretion increased more slowly in acute estrogen deficiency. These data suggest that if an agent is to preserve fully trabecular bone structure, it must be instituted very early in the estrogen- deficient state. They also suggest that a lag time exists before DPD excretion properly mirrors newly induced conditions of high bone turnover in this rat model.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 229-236 |
| Number of pages | 8 |
| Journal | Journal of Bone and Mineral Research |
| Volume | 13 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1998 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Surgery
Cite this
Acute changes in trabecular bone connectivity and osteoclast activity in the ovariectomized rat in vivo. / Lane, Nancy E; Thompson, Jennifer M.; Haupt, David; Kimmel, Donald B.; Modin, Gunnar; Kinney, John H.
In: Journal of Bone and Mineral Research, Vol. 13, No. 2, 1998, p. 229-236.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Acute changes in trabecular bone connectivity and osteoclast activity in the ovariectomized rat in vivo
AU - Lane, Nancy E
AU - Thompson, Jennifer M.
AU - Haupt, David
AU - Kimmel, Donald B.
AU - Modin, Gunnar
AU - Kinney, John H.
PY - 1998
Y1 - 1998
N2 - Estrogen deficiency results in a loss of trabecular bone mass and structure that leads to an increased incidence of osteoporotic fractures. The purpose of this study was to determine the time course for trabecular structure deterioration and changes in bone turnover just after ovariectomy in the rat. Six-month-old female virgin Sprague-Dawley rats had their right proximal tibia scanned by X-ray tomographic microscopy (XTM) at baseline (day 0). Animals were then randomized into two groups, and in each group 9 were sham-operated and 11 were ovariectomized and had repeat XTM scans on days 5, 13, 29, and 42 postovariectomy in group 1 and on days 8, 13, 33, and 50 postovariectomy in group 2. Urine was collected for deoxypyridinoline (DPD) cross-link measurements 24 h before each XTM scan and analyzed by ELISA. Trabecular bone structural variables and bone turnover endpoints were calculated from XTM data and standard histomorphometry. Trabecular connectivity decreased 27% by days 5 and 8 postovariectomy (p < 0.01) and continued to decrease up to day 50 postovariectomy (p < 0.01). The trabecular bone volume decreased 25% by 8 days postovariectomy (p < 0.01), and it continued to decrease through day 50. DPD cross-link excretion had increased 37% on day 13 (p < 0.01) and by over 100% of baseline by day 50 postovariectomy. Trabecular bone connectivity and volume deteriorate rapidly while DPD cross-link excretion increased more slowly in acute estrogen deficiency. These data suggest that if an agent is to preserve fully trabecular bone structure, it must be instituted very early in the estrogen- deficient state. They also suggest that a lag time exists before DPD excretion properly mirrors newly induced conditions of high bone turnover in this rat model.
AB - Estrogen deficiency results in a loss of trabecular bone mass and structure that leads to an increased incidence of osteoporotic fractures. The purpose of this study was to determine the time course for trabecular structure deterioration and changes in bone turnover just after ovariectomy in the rat. Six-month-old female virgin Sprague-Dawley rats had their right proximal tibia scanned by X-ray tomographic microscopy (XTM) at baseline (day 0). Animals were then randomized into two groups, and in each group 9 were sham-operated and 11 were ovariectomized and had repeat XTM scans on days 5, 13, 29, and 42 postovariectomy in group 1 and on days 8, 13, 33, and 50 postovariectomy in group 2. Urine was collected for deoxypyridinoline (DPD) cross-link measurements 24 h before each XTM scan and analyzed by ELISA. Trabecular bone structural variables and bone turnover endpoints were calculated from XTM data and standard histomorphometry. Trabecular connectivity decreased 27% by days 5 and 8 postovariectomy (p < 0.01) and continued to decrease up to day 50 postovariectomy (p < 0.01). The trabecular bone volume decreased 25% by 8 days postovariectomy (p < 0.01), and it continued to decrease through day 50. DPD cross-link excretion had increased 37% on day 13 (p < 0.01) and by over 100% of baseline by day 50 postovariectomy. Trabecular bone connectivity and volume deteriorate rapidly while DPD cross-link excretion increased more slowly in acute estrogen deficiency. These data suggest that if an agent is to preserve fully trabecular bone structure, it must be instituted very early in the estrogen- deficient state. They also suggest that a lag time exists before DPD excretion properly mirrors newly induced conditions of high bone turnover in this rat model.
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UR - http://www.scopus.com/inward/citedby.url?scp=0031942215&partnerID=8YFLogxK
U2 - 10.1359/jbmr.1998.13.2.229
DO - 10.1359/jbmr.1998.13.2.229
M3 - Article
C2 - 9495515
AN - SCOPUS:0031942215
VL - 13
SP - 229
EP - 236
JO - Journal of Bone and Mineral Research
JF - Journal of Bone and Mineral Research
SN - 0884-0431
IS - 2
ER -