Effects of genistein on vertebral trabecular bone microstructure, bone mineral density, microcracks, osteocyte density, and bone strength in ovariectomized rats
- 4 July 2008
- journal article
- Published by Springer Science and Business Media LLC in Journal of Bone and Mineral Metabolism
- Vol. 26 (4), 342-349
- https://doi.org/10.1007/s00774-007-0830-4
Abstract
Until now, the effects of phytoestrogen on bone in both women and ovarian hormone-deficient animal models of osteoporosis have remained uncertain. We have aimed here to investigate the effect of genistein (GEN) on trabecular bone quality in ovariectomized (OVX) rats. Forty 7-month-old female Sprague-Dawley rats were randomly divided into the following four groups: OVX, sham-operated (SHAM), treated with 17β-estradiol (EST, 10 μg·kg−1·day−1), and GEN (5 mg·kg−1·day−1). At 15 weeks postoperation, the compressive test was performed on the L5 vertebral body; additionally, microcomputed tomography (μ-CT) assessment was performed to estimate the bone mineral density (BMD) and microstructure parameters of the L6 vertebral body. After fatigue damage testing, the L6 vertebral body was bulk-stained in 1% basic fuchsin and embedded in methylmethacrylate. The L4 vertebral body was embedded in methylmethacrylate for dynamic histomorphometry analysis without staining. Mounted bone slices were used to measure microcrack parameters, empty osteocyte lacuna density (e.Lc.Dn), and osteocyte density (Ot.N/T.Ar). Maximum loading (ML) and Ot.N/T.Ar were significantly lower in the OVX group than in the other groups. E.Lc.Dn was significantly decreased in GEN and EST groups compared to the OVX group. ML was significantly decreased in the GEN group compared to the SHAM group. Microcrack density, microcrack surface density, and microcrack length were significantly increased in the OVX group compared to the other groups. Mineral apposition rate was significantly decreased in the OVX group compared to the SHAM and GEN groups. Bone formation rate was significantly decreased in the OVX group compared to other groups. There were no significant differences with regard to mineralizing surface among the four groups. Volumetric BMD at organ was significantly lower in OVX, EST, and GEN groups than in the SHAM group. Bone mineral content was significantly lower in the OVX group than in the SHAM group. Bone volume fraction and trabecular number were significantly decreased in OVX, EST, and GEN groups compared to the SHAM group. Structure model index was significantly lower in the SHAM group than in OVX, EST, and GEN groups. Trabecular separation was significantly increased in the OVX group compared to SHAM and EST groups. There were no significant differences with regard to the trabecular thickness (Tb,Th) between SHAM, GEN, and OVX groups. Tb.Th was significantly lower in the EST group than in the SHAM group. Connectivity density (Conn.D) was significantly lower in the OVX group than in SHAM and GEN groups, and Conn. D was significantly lower in the EST group than in GEN. In conclusion, the present study demonstrates that GEN preserved the biomechanical quality of the trabecular bone regardless of the microstructure and BMD.Keywords
This publication has 61 references indexed in Scilit:
- Interrelationships Between Bone Microarchitecture and Strength in Ovariectomized Monkeys Treated With TeriparatideJournal of Bone and Mineral Research, 2007
- Bone quality: what is it and how is it measured?Archives of Endocrinology and Metabolism, 2006
- Osteocytes Use Estrogen Receptor α to Respond to Strain but Their ERα Content Is Regulated by EstrogenJournal of Bone and Mineral Research, 2006
- Osteocyte density in woven boneBone, 2004
- Intermittent Ibandronate Preserves Bone Quality and Bone Strength in the Lumbar Spine After 16 Months of Treatment in the Ovariectomized Cynomolgus MonkeyJournal of Bone and Mineral Research, 2004
- Microcracks: an alternative index for evaluating bone biomechanical qualityJournal of Bone and Mineral Metabolism, 2004
- Effects of estrogen on collagen synthesis by cultured human osteoblasts depend on the rate of cellular differentiationJournal of Cellular Biochemistry, 2002
- Unbiased estimation of vertebral trabecular connectivity in calcium-restricted ovariectomized minipigsBone, 1995
- Relations between histologic indices of bone formation: Implications for the pathogenesis of spinal osteoporosisJournal of Bone and Mineral Research, 1995
- Short-term effects of organic silicon on trabecular bone in mature ovariectomized ratsCalcified Tissue International, 1993