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Bone degeneration and recovery after early and late bisphosphonate treatment of ovariectomized wistar rats assessed by in vivo micro-computed tomography.

Brouwers JE, Lambers FM, Gasser JA, van Rietbergen B, Huiskes R - Calcif. Tissue Int. (2008)

Bottom Line: Late ZOL treatment significantly improved bone microstructure, although the structure did not recover to original levels.Early ZOL treatment resulted in a significantly better microstructure than late treatment.However, late treatment was still significantly better than no treatment.

View Article: PubMed Central - PubMed

Affiliation: Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands. j.e.m.brouwers@tue.nl

ABSTRACT
Bisphosphonates are antiresorptive drugs commonly used to treat osteoporosis. It is not clear, however, what the influence of the time point of treatment is. Recently developed in vivo micro-computed tomographic (CT) scanners offer the possibility to study such effects on bone microstructure in rats. The aim of this study was to determine the influence of early and late zoledronic acid treatment on bone in ovariectomized rats, using in vivo micro-CT. Twenty-nine female Wistar rats were divided into the following groups: ovariectomy (OVX, n = 5), OVX and zoledronic acid (ZOL) at week 0 (n = 8), OVX and ZOL at week 8 (n = 7), and sham (n = 9). CT scans were made of the proximal tibia at weeks 0, 2, 4, 8, 12, and 16; and bone structural parameters were determined in the metaphysis. Two fluorescent labels were administered to calculate dynamic histomorphometric parameters. At week 16, all groups were significantly different from each other in bone volume fraction (BV/TV), connectivity density, and trabecular number (Tb.N), except for the early ZOL and control groups which were not significantly different for any structural parameter. After ZOL treatment at week 8, BV/TV, structure model index, Tb.N, and trabecular thickness significantly improved in the late ZOL group. The OVX and ZOL groups showed, respectively, higher and lower bone formation rates than the control group. Early ZOL treatment inhibited all bone microstructural changes seen after OVX. Late ZOL treatment significantly improved bone microstructure, although the structure did not recover to original levels. Early ZOL treatment resulted in a significantly better microstructure than late treatment. However, late treatment was still significantly better than no treatment.

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Dynamic bone histomorphometric parameters for all groups in the metaphyseal proximal tibia. Groups: 1, control; 2, OVX; 3, late ZOL; 4, early ZOL. Based on ANOVA and a Bonferroni test, asignificantly different from group 1, bsignificantly different from group 2, csignificantly different from group 3, and dsignificantly different from group 4 (P < 0.05)
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Fig5: Dynamic bone histomorphometric parameters for all groups in the metaphyseal proximal tibia. Groups: 1, control; 2, OVX; 3, late ZOL; 4, early ZOL. Based on ANOVA and a Bonferroni test, asignificantly different from group 1, bsignificantly different from group 2, csignificantly different from group 3, and dsignificantly different from group 4 (P < 0.05)

Mentions: Histomorphometric results were obtained for five (control), five (OVX), six (OVX and late ZOL), and five (OVX and early ZOL) rats. The OVX group showed a significantly higher mineralizing surface (MS/BS) and BFR and a substantially higher mineral apposition rate (MAR) than the control group (Fig. 5). Both ZOL groups showed a significantly lower MS/BS and BFR than the OVX group and control group, while MAR was significantly lower than only the OVX group. Additionally, the late ZOL group had a significantly lower MS/BS and a nonsignificantly lower BFR than the early ZOL group.Fig. 5


Bone degeneration and recovery after early and late bisphosphonate treatment of ovariectomized wistar rats assessed by in vivo micro-computed tomography.

Brouwers JE, Lambers FM, Gasser JA, van Rietbergen B, Huiskes R - Calcif. Tissue Int. (2008)

Dynamic bone histomorphometric parameters for all groups in the metaphyseal proximal tibia. Groups: 1, control; 2, OVX; 3, late ZOL; 4, early ZOL. Based on ANOVA and a Bonferroni test, asignificantly different from group 1, bsignificantly different from group 2, csignificantly different from group 3, and dsignificantly different from group 4 (P < 0.05)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2268729&req=5

Fig5: Dynamic bone histomorphometric parameters for all groups in the metaphyseal proximal tibia. Groups: 1, control; 2, OVX; 3, late ZOL; 4, early ZOL. Based on ANOVA and a Bonferroni test, asignificantly different from group 1, bsignificantly different from group 2, csignificantly different from group 3, and dsignificantly different from group 4 (P < 0.05)
Mentions: Histomorphometric results were obtained for five (control), five (OVX), six (OVX and late ZOL), and five (OVX and early ZOL) rats. The OVX group showed a significantly higher mineralizing surface (MS/BS) and BFR and a substantially higher mineral apposition rate (MAR) than the control group (Fig. 5). Both ZOL groups showed a significantly lower MS/BS and BFR than the OVX group and control group, while MAR was significantly lower than only the OVX group. Additionally, the late ZOL group had a significantly lower MS/BS and a nonsignificantly lower BFR than the early ZOL group.Fig. 5

Bottom Line: Late ZOL treatment significantly improved bone microstructure, although the structure did not recover to original levels.Early ZOL treatment resulted in a significantly better microstructure than late treatment.However, late treatment was still significantly better than no treatment.

View Article: PubMed Central - PubMed

Affiliation: Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands. j.e.m.brouwers@tue.nl

ABSTRACT
Bisphosphonates are antiresorptive drugs commonly used to treat osteoporosis. It is not clear, however, what the influence of the time point of treatment is. Recently developed in vivo micro-computed tomographic (CT) scanners offer the possibility to study such effects on bone microstructure in rats. The aim of this study was to determine the influence of early and late zoledronic acid treatment on bone in ovariectomized rats, using in vivo micro-CT. Twenty-nine female Wistar rats were divided into the following groups: ovariectomy (OVX, n = 5), OVX and zoledronic acid (ZOL) at week 0 (n = 8), OVX and ZOL at week 8 (n = 7), and sham (n = 9). CT scans were made of the proximal tibia at weeks 0, 2, 4, 8, 12, and 16; and bone structural parameters were determined in the metaphysis. Two fluorescent labels were administered to calculate dynamic histomorphometric parameters. At week 16, all groups were significantly different from each other in bone volume fraction (BV/TV), connectivity density, and trabecular number (Tb.N), except for the early ZOL and control groups which were not significantly different for any structural parameter. After ZOL treatment at week 8, BV/TV, structure model index, Tb.N, and trabecular thickness significantly improved in the late ZOL group. The OVX and ZOL groups showed, respectively, higher and lower bone formation rates than the control group. Early ZOL treatment inhibited all bone microstructural changes seen after OVX. Late ZOL treatment significantly improved bone microstructure, although the structure did not recover to original levels. Early ZOL treatment resulted in a significantly better microstructure than late treatment. However, late treatment was still significantly better than no treatment.

Show MeSH
Related in: MedlinePlus