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Li H, Gou Y, Tian F, Lian Q, Hu Y, Zhang L. The combined anti-osteoporotic effects of simvastatin and exercise in ovariectomized mice fed a high-fat diet. Exp Gerontol 2022; 164:111794. [PMID: 35421557 DOI: 10.1016/j.exger.2022.111794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/13/2022] [Accepted: 03/29/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND To evaluate and compare the effects of the combined intervention of simvastatin and exercise on the bone degeneration in a mice model of osteoporosis (OP) induced by obesity and estrogen deficiency. METHODS 56 female 3-month-old C57BL/6 mice were given a standard diet or a high-fat diet after ovariectomy (OVX) or sham surgery. Drug administration and exercise training were initiated 72 h after surgical operation, which were treated with simvastatin (10 mg/kg/day) or exercise (15 m/min for 30 min/day) or combined with simvastatin and exercise at 72 h for 8 weeks. The pathology of OP was assessed by histomorphology analyses, immunohistochemistry (IHC), micro-computed tomography (Micro-CT), enzyme-linked immunosorbent assay (ELISA) and cell culture. RESULTS The coexistence of obesity and estrogen deficiency significantly further exacerbated OP pathology, and combined intervention showed a better significant anti-osteoporosis effect than monotherapy. In details, simvastatin combined with exercise ameliorated the abnormal bone mass, microstructure and bone marrow adipocyte differentiation, significantly increased osteoprotegerin (OPG), type 1 collagen (Col-I), RUNX2 and osteocalcin (OCN) expression, decreased the expression of receptor activator of nuclear factor-kappaB ligand (RANKL) and peroxisome proliferator-activated receptor γ (PPARγ). Furthermore, combined intervention markedly improved abnormal metabolic status, reduced the levels of serum glucose, insulin, triglycerides (TG), low-density lipoprotein (LDL), leptin, CTX-1 and IL-1β, and increased the level of OCN. CONCLUSIONS The coexistence of obesity and estrogen deficiency further aggravates bone tissue degeneration and abnormal metabolic pathology, which could be better inhibited by the combination with simvastatin and exercise instead of single intervention, suggesting that combined intervention may be a potential candidate for amelioration of the progression of OP.
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Affiliation(s)
- Hetong Li
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, PR China
| | - Yu Gou
- Department of Orthopaedic Surgery, Tianjin Hospital, Tianjin University, Tianjin, PR China
| | - Faming Tian
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, PR China
| | - Qiangqiang Lian
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, PR China
| | - Yunpeng Hu
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, PR China
| | - Liu Zhang
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, PR China.
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Li H, Gou Y, Tian F, Zhang Y, Lian Q, Hu Y, Zhang L. Combination of metformin and exercise alleviates osteoarthritis in ovariectomized mice fed a high-fat diet. Bone 2022; 157:116323. [PMID: 34990878 DOI: 10.1016/j.bone.2021.116323] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 12/10/2021] [Accepted: 12/28/2021] [Indexed: 01/04/2023]
Abstract
OBJECTIVE To evaluate and compare the effects of the combined intervention of metformin and exercise on the degeneration of cartilage and subchondral bone in a mouse model of osteoarthritis (OA) induced by estrogen deficiency and obesity. METHODS 56 female 3-month-old C57BL/6 mice underwent ovariectomy (OVX) (n = 40) or a sham operation (n = 16) and were randomized into seven groups (n = 8/group): 1) sham-operated mice with a normal diet (Sham), 2) OVX mice with a normal diet (OVX), 3) sham-operated mice with high-fat diet (HFD) (HSVX), 4) OVX mice with HFD (HOVX), 5) OVX mice with HFD + exercise (HOVE), 6) OVX mice with HFD + metformin (HOMX), and 7) OVX mice with HFD + metformin + exercise (HOME). Drug administration and exercise training were initiated 72 h after surgical operation. The pathology of OA was assessed by histomorphology analyses, immunohistochemistry (IHC), tartrate-resistant acid phosphatase (TRAP) staining, micro-computed tomography and enzyme-linked immunosorbent assay (ELISA). RESULTS Histomorphological analysis revealed that OA was significantly exacerbated by the coexistence of estrogen deficiency and obesity and markedly alleviated by the combined intervention. In details, metformin plus exercise ameliorated the abnormal metabolic status and cartilage lesions, significantly increased aggrecan and collagen-II expression and decreased the expression of ADAMTS-4. Furthermore, combined intervention markedly improved bone degeneration, bone mass and microarchitecture of subchondral bone. And the intervention also increased the concentration of OCN and decreased the serum concentration of IL-1β and CTX-1 and glucose. CONCLUSIONS The coexistence of estrogen deficiency and obesity further aggravates abnormal metabolic pathology and articular degeneration, which could be prevented by the combination with metformin and exercise, suggesting that combined intervention may be a potential candidate for amelioration of the progression of OA.
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Affiliation(s)
- Hetong Li
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, PR China.
| | - Yu Gou
- Department of Orthopaedic Surgery, Tianjin Hospital, Tianjin University, Tianjin, PR China.
| | - Faming Tian
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, PR China.
| | - Ya Zhang
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, PR China
| | - Qiangqiang Lian
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei, PR China
| | - Yunpeng Hu
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, PR China
| | - Liu Zhang
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, PR China.
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Ju YI, Sone T. Effects of Different Types of Mechanical Loading on Trabecular Bone Microarchitecture in Rats. J Bone Metab 2021; 28:253-265. [PMID: 34905673 PMCID: PMC8671029 DOI: 10.11005/jbm.2021.28.4.253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/06/2021] [Indexed: 11/21/2022] Open
Abstract
Mechanical loading is generally considered to have a positive impact on the skeleton; however, not all types of mechanical loading have the same beneficial effect. Many researchers have investigated which types of mechanical loading are more effective for improving bone mass and strength. Among the various mechanical loads, high-impact loading, such as jumping, appears to be more beneficial for bones than low-impact loadings such as walking, running, or swimming. Therefore, the different forms of mechanical loading exerted by running, swimming, and jumping exercises may have different effects on bone adaptations. However, little is known about the relationships between the types of mechanical loading and their effects on trabecular bone structure. The purpose of this article is to review the recent reports on the effects of treadmill running, jumping, and swimming on the trabecular bone microarchitecture in small animals. The effects of loading on trabecular bone architecture appear to differ among these different exercises, as several reports have shown that jumping increases the trabecular bone mass by thickening the trabeculae, whereas treadmill running and swimming add to the trabecular bone mass by increasing the trabecular number, rather than the thickness. This suggests that different types of exercise promote gains in trabecular bone mass through different architectural patterns in small animals.
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Affiliation(s)
- Yong-In Ju
- Department of Health and Sports Sciences, Kawasaki University of Medical Welfare, Kurashiki, Okayama, Japan
| | - Teruki Sone
- Department of Nuclear Medicine, Kawasaki Medical School, Kurashiki, Okayama, Japan
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Nepal AK, van Essen HW, van der Veen AJ, van Wieringen WN, Stavenuiter AWD, Cayami FK, Pals G, Micha D, Vanderschueren D, Lips P, Bravenboer N. Mechanical stress regulates bone regulatory gene expression independent of estrogen and vitamin D deficiency in rats. J Orthop Res 2021; 39:42-52. [PMID: 32530517 PMCID: PMC7818391 DOI: 10.1002/jor.24775] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 05/13/2020] [Accepted: 05/25/2020] [Indexed: 02/04/2023]
Abstract
Mechanical stress determines bone mass and structure. It is not known whether mechanical loading affects expression of bone regulatory genes in a combined deficiency of estrogen and vitamin D. We studied the effect of mechanical loading on the messenger RNA (mRNA) expression of bone regulatory genes during vitamin D and/or estrogen deficiency. We performed a single bout in vivo axial loading with 14 N peak load, 2 Hz frequency and 360 cycles in right ulnae of nineteen weeks old female control Wistar rats with or without ovariectomy (OVX), vitamin D deficiency and the combination of OVX and vitamin D deficiency (N = 10/group). Total bone RNA was isolated 6 hours after loading, and mRNA expression was detected of Mepe, Fgf23, Dmp1, Phex, Sost, Col1a1, Cyp27b1, Vdr, and Esr1. Serum levels of 25(OH)D, 1,25(OH)2 D and estradiol were also measured at this time point. The effect of loading, vitamin D and estrogen deficiency and their interaction on bone gene expression was tested using a mixed effect model analysis. Mechanical loading significantly increased the mRNA expression of Mepe, and Sost, whereas it decreased the mRNA expression of Fgf23 and Esr1. Mechanical loading showed a significant interaction with vitamin D deficiency with regard to mRNA expression of Vdr and Esr1. Mechanical loading affected gene expression of Mepe, Fgf23, Sost, and Esr1 independently of vitamin D or estrogen, indicating that mechanical loading may affect bone turnover even during vitamin D deficiency and after menopause.
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Affiliation(s)
- Ashwini Kumar Nepal
- Department of Clinical Chemistry, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
| | - Huib W. van Essen
- Department of Clinical Chemistry, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
| | - Albert J. van der Veen
- Department of Physics and Medical Technology, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Wessel N. van Wieringen
- Department of Epidemiology and Biostatistics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Department of MathematicsVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Andrea W. D. Stavenuiter
- Department of Molecular Cell Biology and Immunology, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Ferdy Kurniawan Cayami
- Department of Clinical Genetics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Department of Anatomy, Center for Biomedical Research, Faculty of MedicineDiponegoro UniversitySemarangIndonesia
| | - Gerard Pals
- Department of Clinical Genetics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Dimitra Micha
- Department of Clinical Genetics, Amsterdam UMCVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Dirk Vanderschueren
- Laboratory of Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism, and AgeingKU LeuvenLeuvenBelgium
| | - Paul Lips
- Endocrine Section, Department of Internal Medicine, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
- Endocrine Section, Department of Internal Medicine, Amsterdam UMCVrije Universiteit Amsterdam, Amsterdam Movement SciencesAmsterdamThe Netherlands
- Division Endocrinology, Department of Internal Medicine, Center of Bone QualityLeiden University Medical CenterLeidenThe Netherlands
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Portier H, Benaitreau D, Pallu S. Does Physical Exercise Always Improve Bone Quality in Rats? Life (Basel) 2020; 10:life10100217. [PMID: 32977460 PMCID: PMC7598192 DOI: 10.3390/life10100217] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/17/2022] Open
Abstract
For decades, the osteogenic effect from different physical activities on bone in rodents remained uncertain. This literature review presents for the first time the effects on five exercise models (treadmill running, wheel running, swimming, resistance training and vibration modes) in three different experimental rat groups (males, females, osteopenic) on bone quality. The bone parameters presented are bone mineral density, micro-architectural and mechanical properties, and osteoblast/osteocyte and osteoclast parameters. This review shows that physical activities have a positive effect (65% of the results) on bone status, but we clearly observed a difference amongst the different protocols. Even if treadmill running is the most used protocol, the resistance training constitutes the first exercise model in term of osteogenic effects (87% of the whole results obtained on this model). The less osteogenic model is the vibration mode procedure (31%). It clearly appears that the gender plays a role on the bone response to swimming and wheel running exercises. Besides, we did not observe negative results in the osteopenic population with impact training, wheel running and vibration activities. Moreover, about osteoblast/osteocyte parameters, we conclude that high impact and resistance exercise (such jumps and tower climbing) seems to increase bone formation more than running or aerobic exercise. Among the different protocols, literature has shown that the treadmill running procedure mainly induces osteogenic effects on the viability of the osteocyte lineage in both males and females or ovariectomized rats; running in voluntary wheels contributes to a negative effect on bone metabolism in older male models; whole-body vertical vibration is not an osteogenic exercise in female and ovariectomized rats; whereas swimming provides controversial results in female models. For osteoclast parameters only, running in a voluntary wheel for old males, the treadmill running program at high intensity in ovariectomized rats, and the swimming program in a specific ovariectomy condition have detrimental consequences.
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Affiliation(s)
- Hugues Portier
- Laboratoire de Biologie Bioingénierie et Bioimagerie Ostéo-Articulaire (B3OA), Université Paris, UMR CNRS 7052, INSERM U1273, 10 Av de Verdun, 75010 Paris, France;
- Collegium Science & Technique, 2 allée du château, Université d’Orléans. 45100 Orléans, France;
- Correspondence: ; Tel.: +33-782-309-433
| | - Delphine Benaitreau
- Collegium Science & Technique, 2 allée du château, Université d’Orléans. 45100 Orléans, France;
| | - Stéphane Pallu
- Laboratoire de Biologie Bioingénierie et Bioimagerie Ostéo-Articulaire (B3OA), Université Paris, UMR CNRS 7052, INSERM U1273, 10 Av de Verdun, 75010 Paris, France;
- Collegium Science & Technique, 2 allée du château, Université d’Orléans. 45100 Orléans, France;
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Fu D, Qin K, Yang S, Lu J, Lian H, Zhao D. Proper mechanical stress promotes femoral head recovery from steroid-induced osteonecrosis in rats through the OPG/RANK/RANKL system. BMC Musculoskelet Disord 2020; 21:281. [PMID: 32359349 PMCID: PMC7196225 DOI: 10.1186/s12891-020-03301-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/21/2020] [Indexed: 12/15/2022] Open
Abstract
Background Long-term use of steroid may lead to osteonecrosis of the femoral head (ONFH). Mechanical stress may help bone formation and remodeling. This study aimed to probe the role of mechanical stress in the femoral head recovery in rats. Methods Rat models with ONFH were induced by steroid. Rats were subjected to different levels of mechanical stress (weight-bearing training), and then the morphology and bone density of femoral head of rats were measured. The mRNA and protein levels of the OPG/RANK/RANKL axis in rat femoral head were assessed. Gain- and loss-of function experiments of OPG were performed to identify its role in femoral head recovery following stress implement. The ex vivo cells were extracted and the effects of stress and OPG on osteogenesis in vitro were explored. Results Steroid-induced ONFH rats showed decreased bone density and increased bone spaces, as well as necrotic cell colonies and many cavities in the cortical bones and trabeculars. Proper mechanical stress or upregulation of OPG led to decreased RANK/RANKL expression and promoted femoral head recovery from steroid-induced osteonecrosis. However, excessive mechanical stress might impose too much load on the femurs thus leading even retard femoral head recovery process. In addition, the in vitro experimental results supported that proper stress and overexpression of OPG increased the osteogenesis of ex vivo cells of femoral head. Conclusion This study provided evidence that proper mechanical stress promoted femoral head recovery from steroid-induced osteonecrosis through the OPG/RANK/RANKL system, while overload might inhibit the recovery process. This study may offer novel insights for ONFH treatment.
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Affiliation(s)
- Dapeng Fu
- Department of Biomedical engineering, Dalian University of Technology, Dalian, 116024, Liaoning, People's Republic of China.,Department of Orthopaedics, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Zhongshan District, Dalian, 116001, Liaoning, People's Republic of China
| | - Kairong Qin
- Department of Biomedical engineering, Dalian University of Technology, Dalian, 116024, Liaoning, People's Republic of China
| | - Sheng Yang
- Department of Orthopaedics, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Zhongshan District, Dalian, 116001, Liaoning, People's Republic of China
| | - Jianmin Lu
- Department of Orthopaedics, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Zhongshan District, Dalian, 116001, Liaoning, People's Republic of China
| | - Haoyi Lian
- Department of Orthopaedics, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Zhongshan District, Dalian, 116001, Liaoning, People's Republic of China
| | - Dewei Zhao
- Department of Biomedical engineering, Dalian University of Technology, Dalian, 116024, Liaoning, People's Republic of China. .,Department of Orthopaedics, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Zhongshan District, Dalian, 116001, Liaoning, People's Republic of China.
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7
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Kawao N, Ishida M, Kaji H. Roles of leptin in the recovery of muscle and bone by reloading after mechanical unloading in high fat diet-fed obese mice. PLoS One 2019; 14:e0224403. [PMID: 31648235 PMCID: PMC6812756 DOI: 10.1371/journal.pone.0224403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/11/2019] [Indexed: 01/31/2023] Open
Abstract
Muscle and bone masses are elevated by the increased mechanical stress associated with body weight gain in obesity. However, the mechanisms by which obesity affects muscle and bone remain unclear. We herein investigated the roles of obesity and humoral factors from adipose tissue in the recovery phase after reloading from disuse-induced muscle wasting and bone loss using normal diet (ND)- or high fat diet (HFD)-fed mice with hindlimb unloading (HU) and subsequent reloading. Obesity did not affect decreases in trabecular bone mineral density (BMD), muscle mass in the lower leg, or grip strength in HU mice. Obesity significantly increased trabecular BMD, muscle mass in the lower leg, and grip strength in reloading mice over those in reloading mice fed ND. Among the humoral factors in epididymal and subcutaneous adipose tissue, leptin mRNA levels were significantly higher in reloading mice fed HFD than in mice fed ND. Moreover, circulating leptin levels were significantly higher in reloading mice fed HFD than in mice fed ND. Leptin mRNA levels in epididymal adipose tissue or serum leptin levels positively correlated with the increases in trabecular BMD, total muscle mass, and grip strength in reloading mice fed ND and HFD. The present study is the first to demonstrate that obesity enhances the recovery of bone and muscle masses as well as strength decreased by disuse after reloading in mice. Leptin may contribute to the recovery of muscle and bone enhanced by obesity in mice.
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Affiliation(s)
- Naoyuki Kawao
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Masayoshi Ishida
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Hiroshi Kaji
- Department of Physiology and Regenerative Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
- * E-mail:
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8
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Fang J, Gao J, Gong H, Zhang T, Zhang R, Zhan B. Multiscale experimental study on the effects of different weight-bearing levels during moderate treadmill exercise on bone quality in growing female rats. Biomed Eng Online 2019; 18:33. [PMID: 30902108 PMCID: PMC6431042 DOI: 10.1186/s12938-019-0654-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 03/15/2019] [Indexed: 01/16/2023] Open
Abstract
Background Bone tissue displays a hierarchical organization. Mechanical environments influence bone mass and structure. This study aimed to explore the effects of different mechanical stimuli on growing bone properties at macro–micro–nano scales. Methods Sixty five-week-old female Wistar rats were treadmill exercised at moderate intensity with the speed of 12 m/min, and then randomly divided into five groups according to weight-bearing level. After 8 weeks of experiment, femurs were harvested to perform multiscale tests. Results Bone formation was significantly increased by weight-bearing exercise, whereas bone resorption was not significantly inhibited. Trabecular and cortical bone mineral densities showed no significant increase by weight-bearing exercise. The microstructure of trabecular bone was significantly improved by 12% weight-bearing exercise. However, similar positive effects were not observed with further increase in weight-bearing levels. The nanomechanical properties of trabecular bone were not significantly changed by weight-bearing exercise. The macrostrength of whole femur and the nanomechanical properties of cortical bone significantly decreased in the 19% and 26% weight-bearing exercise groups. Conclusion When rats ran on the treadmill at moderate intensity during growth period, additional 12% weight-bearing level could significantly increase bone formation, improve microstructure of trabecular bone, as well as maintain the structure and mechanical properties of cortical bone. Excessive weight-bearing level caused no positive effects on the trabecular bone microstructure and properties of cortical bone at all scales. In addition, increased weight-bearing level exerted no significant influence on trabecular and cortical bone mineral densities.
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Affiliation(s)
- Juan Fang
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China.,School of Civil Engineering, Jilin Jianzhu University, Changchun, 130118, People's Republic of China
| | - Jiazi Gao
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China
| | - He Gong
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China.
| | - Tianlong Zhang
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China
| | - Rui Zhang
- School of Biomedical Science and Medical Engineering, Beihang Univerisity, Beijing, 100191, People's Republic of China
| | - Bangchao Zhan
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China
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9
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Zhang T, Gao J, Fang J, Gong H. Multiscale investigation on the effects of additional weight bearing in combination with low-magnitude high-frequency vibration on bone quality of growing female rats. J Bone Miner Metab 2018; 36:157-169. [PMID: 28293780 DOI: 10.1007/s00774-017-0827-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 02/15/2017] [Indexed: 11/29/2022]
Abstract
This study aimed to explore the effects of additional weight bearing in combination with low-magnitude high-frequency vibration (LMHFV; 45 Hz, 0.3 g) on bone quality. One hundred twenty rats were randomly divided into ten groups; namely, sedentary (SED), additional weight bearing in which the rat wears a backpack whose weight is x% of the body weight (WBx; x = 5, 12, 19, 26), basic vibration (V), and additional weight bearing in combination with LMHFV in which the rat wears a backpack whose weight is x% of the body weight (Vx; x = 5, 12, 19, 26). The experiment was conducted for 12 weeks, 7 days per week, and 15 min per day. A three-point bending mechanical test, micro computed tomography, and a nanoindentation test were used. Serum samples were analyzed chemically. Failure load in V19 rats was significantly lower than that in SED rats (P < 0.05). Vx (x = 5, 12, 19, 26) rats showed poor microarchitectures. The content of tartrate-resistant acid phosphatase 5b was significantly higher in Vx (x = 5, 12, 19, 26) rats than that in SED rats (P < 0.05). V26 rats demonstrated comparatively better nanomechanical properties of materials than the other vibrational groups. Additional weight bearing in combination with LMHFV negatively affected the macromechanical properties and microarchitecture of bone. Heavy additional weight bearing, such as 26% of body weight, in combination with LMHFV was able to improve the nanomechanical properties of growing bone material compared with LMHFV. A combined mechanical stimulation was used, which may provide useful information to understand the mechanism of this mechanical stimulation on bone.
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Affiliation(s)
- Tianlong Zhang
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China
| | - Jiazi Gao
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China
| | - Juan Fang
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China
| | - He Gong
- Department of Engineering Mechanics, Jilin University, Changchun, 130022, People's Republic of China.
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10
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Shimano RC, Yanagihara GR, Macedo AP, Yamanaka JS, Shimano AC, Tavares JMRS, Issa JPM. Effects of high-impact exercise on the physical properties of bones of ovariectomized rats fed to a high-protein diet. Scand J Med Sci Sports 2018; 28:1523-1531. [PMID: 29345841 DOI: 10.1111/sms.13058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2017] [Indexed: 01/08/2023]
Abstract
The aim of this study was to evaluate the effects of high-impact physical exercise as a prophylactic and therapeutic means in osteopenic bones of rats submitted to ovariectomy and protein diet intake. A total of 64 Wistar rats were divided into eight groups (n = 8 each), being: OVX, ovx, standard diet and sedentary; OVXE, ovx, standard diet and jump; OVXP, ovx, high-protein diet and sedentary; and OVXEP, ovx, high-protein diet and jump; SH, sham, standard diet and sedentary; SHE, sham, standard diet and jump; SHP, sham, high-protein diet and sedentary; and SHEP, sham, high-protein diet and jump. OVX surgery consists of ovariectomy, and sham was the control surgery. The jumping protocol consisted of 20 jumps/day, 5 days/week. The bone structure was evaluated by densitometry, mechanical tests, histomorphometric, and immunohistochemical analyses. A high-protein diet resulted in increased bone mineral density (P = .049), but decreased maximal load (P = .026) and bone volume fraction (P = .023). The benefits of physical exercise were demonstrated by higher values of the maximal load in the trained groups compared to the sedentary groups (P < .001). The sham groups had decreased immunostaining of osteocalcin (P = .004) and osteopontin (P = .010) compared to ovx groups. However, the high-protein diet (P = .005) and jump exercise (P = .017) resulted in lower immunostaining of osteopontin compared to the standard diet and sedentary groups, respectively. In this experimental model, it was concluded that ovariectomy and a high-fat diet can negatively affect bone tissue and the high-impact exercise was not enough to suppress the deleterious effects caused by the protein diet and ovariectomy.
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Affiliation(s)
- R C Shimano
- Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - G R Yanagihara
- Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - A P Macedo
- Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - J S Yamanaka
- Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - A C Shimano
- Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - J M R S Tavares
- Instituto de Ciência e Inovação em Engenharia Mecânica e Engenharia Industrial, Departamento de Engenharia Mecânica, Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
| | - J P M Issa
- Departamento de Morfologia, Fisiologia e Patologia Básica, Faculdade de odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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11
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Bravenboer N, van Rens BTTM, van Essen HW, van Dieën JH, Lips P. Ground reaction forces during walking with different load and slope combinations in rats. J Exp Orthop 2017; 4:28. [PMID: 28861752 PMCID: PMC5578952 DOI: 10.1186/s40634-017-0102-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/26/2017] [Indexed: 02/03/2023] Open
Abstract
Background Treadmill animal models are commonly used to study effects of exercise on bone. Since mechanical loading induces bone strain, resulting in bone formation, exercise that induces higher strains is likely to cause more bone formation. Our aim was to investigate the effect of slope and additional load on limb bone strain. Methods Horizontal and vertical ground reaction forces on left fore-limb (FL) and hind-limb (HL) of twenty 23-week old female Wistar rats (weight 279 ± 26 g) were measured for six combinations of SLOPE (−10°, 0°, +10°) and LOAD (0 to 23% of body mass). Peak force (Fmax), rate of force rise (RC), stance time (Tstance) and impulse (Fint) on FLs and HLs were analyzed. Results For the FL, peak ground reaction forces and rate of force rise were highest when walking downward −10° with load (Fmax = 2.09±0.05 N, FLRC = 34±2 N/s) For the HL, ground reaction forces and rate of force rise were highest when walking upward +10°, without load (Fmax = 2.20±0.05 N, HLRC = 34±1 N/s). Load increased stance time. Without additional load, estimates for the highest FL loading (slope is −10°) were larger than for the highest HL loading (slope is +10°) relative to level walking. Conclusions Thus, walking downward has a higher impact on FL bones, while walking upward is a more optimal HL exercise. Additional load may have a small effect on FL loading. Electronic supplementary material The online version of this article (doi:10.1186/s40634-017-0102-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- N Bravenboer
- Amsterdam Movement Sciences, Department of Clinical Chemistry, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, the Netherlands.
| | - B T T M van Rens
- Amsterdam Movement Sciences, Department of Clinical Chemistry, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, the Netherlands
| | - H W van Essen
- Amsterdam Movement Sciences, Department of Clinical Chemistry, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, the Netherlands
| | - J H van Dieën
- Amsterdam Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - P Lips
- Department Internal Medicine, VU University Medical Center, Amsterdam, the Netherlands
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Oh T, Tanaka S, Naka T, Igawa S. Effects of high-intensity swimming training on the bones of ovariectomized rats. J Exerc Nutrition Biochem 2016; 20:39-45. [PMID: 27757386 PMCID: PMC5067419 DOI: 10.20463/jenb.2016.09.20.3.6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/20/2016] [Accepted: 07/25/2016] [Indexed: 11/29/2022] Open
Abstract
[Purpose] This study was performed to assess the effects of high-intensity intermittent swimming training(HIT) on bone in ovariectomized rats. [Methods] Six-week-old female Sprague-Dawley rats were randomly assigned to either sham operation or bilateral ovariectomy. After surgery, they were divided into the following four groups: 1) sham-operated sedentary (S), 2) sham-operated exercise training (SE), 3) OVX sedentary (O), 4) OVX exercise training (OE) 5) OVX given 17β-estradiol (OE2) and 6) OVX exercise training and given 17β-estradiol (OEE). SE, OE and OEE rats were used extremely high-intensity swim exercise. The rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 5, the next 9, and the last 5 days, respectively. Between exercise bouts, a 10-s pause was allowed. HIT was originally designed as an exercise method; a method that very quickly induces an increase in the maximum oxygen intake (Tabata I et al., 1996). OEE and OE2 rats were subcutaneously injected ethanol with 25μg/kg body weight 17β-estradiol 3 times per week. [Results] Bone strength, bone mineral density and trabecular bone parameters were measured after a 8-weeks experimental period. Bone strength was significantly higher in the SE, OE, OE2 and OEE group compared with the O group. BV/TV was significant increase in the SE, OE groups compared with the O group. BMD showed no difference in the OE group compared with the O group. [Conclusion] This study demonstrate some beneficial effects of postmenopausal osteoporosis of high-intensity intermittent swimming training on bone structure and strength.
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Affiliation(s)
- Taewoong Oh
- Dean of the College of Sports Sciences, Yongin University, Yongin-Si Republic of Korea
| | - Sakura Tanaka
- Graduate School of Health Science, Matsumoto University, Nagano Japan
| | - Tatsuki Naka
- Faculty of Wellness, Shigakkan University, Aichi Japan
| | - Shoji Igawa
- Graduate School of Health Science, Matsumoto University, Nagano Japan
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Lee S, Suzuki T, Izawa H, Satoh A. The Influence of the Type of Continuous Exercise Stress Applied during Growth Periods on Bone Metabolism and Osteogenesis. J Bone Metab 2016; 23:157-64. [PMID: 27622180 PMCID: PMC5018609 DOI: 10.11005/jbm.2016.23.3.157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/01/2016] [Accepted: 08/01/2016] [Indexed: 11/26/2022] Open
Abstract
Background In this study, we examined the influence of exercise loading characteristics on bone metabolic responses and bone morphology in the growth phase and adulthood. Methods Running exercise (RUN) and jumping exercise (JUM) were used for the exercise loading in 28-day-old male Wistar rats. Bone metabolism was measured by blood osteocalcin (OC) and tartrate-resistant acid phosphatase (TRACP) levels. For bone morphology, the maximum bone length, bone weight, and bone strength of the femur and tibia were measured. Results A pre- and post-exercise loading comparison in the growth phase showed significantly increased OC levels in the RUN and JUM groups and significantly decreased TRACP levels in the JUM group. On the other hand, a pre- and post-exercise loading comparison in adulthood showed significantly decreased TRACP levels in the RUN and JUM groups. Femur lengths were significantly shorter in the RUN and JUM groups than in the control (CON) group, while bone weight was significantly greater in the JUM group than in the CON group. Conclusions Exercise loading activates OC levels in the growth phase and suppresses TRACP levels in adulthood. On the other hand, these results suggest that excessive exercise loading may suppress bone length.
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Affiliation(s)
- Sangun Lee
- Department of Physical Therapy, Aomori University of Health and Welfare, Aomori, Japan
| | - Takao Suzuki
- Department of Physical Therapy, Aomori University of Health and Welfare, Aomori, Japan
| | - Hiromi Izawa
- Department of Nutrition, Aomori University of Health and Welfare, Aomori, Japan
| | - Atsuko Satoh
- Department of Nursing, Hirosaki University of Health and Welfare, Hirosaki, Japan
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Stringhetta-Garcia CT, Singulani MP, Santos LF, Louzada MJQ, Nakamune ACS, Chaves-Neto AH, Rossi AC, Ervolino E, Dornelles RCM. The effects of strength training and raloxifene on bone health in aging ovariectomized rats. Bone 2016; 85:45-54. [PMID: 26812611 DOI: 10.1016/j.bone.2015.11.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 11/09/2015] [Accepted: 11/28/2015] [Indexed: 11/23/2022]
Abstract
The aim of this study was to investigate the effects of strength training (ST) and raloxifene (Ral), alone or in combination, on the prevention of bone loss in an aging estrogen-deficient rat model. Aging Wistar female rats were ovariectomized at 14months and allocated to four groups: (1) non-trained and treated with vehicle, NT-Veh; (2) strength training and treated with vehicle, ST-Veh; (3) non-trained and treated with raloxifene, NT-Ral; and (4) strength training and treated with raloxifene, ST-Ral. ST was performed on a ladder three times per week and Ral was administered daily by gavage (1mg/kg/day), both for 120days. Areal bone mineral density (aBMD), strength, microarchitecture, and biomarkers (osteocalcin, OCN; osteoprotegerin, OPG; and tartrate-resistant acid phosphatase, TRAP) were assessed. Immunohistochemistry was performed for runt-related transcription factor 2 (RUNX2), osterix (OSX), OCN, OPG, TRAP, and receptor activator of nuclear factor kappa-B ligand (RANKL). The rats that performed ST (ST-Veh) or were treated with Ral (NT-Ral) showed significant improvements in aBMD (p=0.001 and 0.004), bone strength (p=0.001), and bone microarchitecture, such as BV/TV (%) (p=0.001), BS/TV (mm(2)/mm(3)) (p=0.023 and 0.002), Conn.Dn (1/mm(3)) (p=0.001), Tb.N (1/mm) (p=0.012 and 0.011), Tb.Th (1/mm) (p=0.001), SMI (p=0.001 and 0.002), Tb.Sp (p=0.001), and DA (p=0.002 and 0.007); there was also a significant decrease in plasma levels of OCN (p=0.001 and 0.002) and OPG (p=0.003 and 0.014), compared with animals in the NT-Veh group. Ral, with or without ST, promoted an increased immunolabeling pattern for RUNX2 (p=0.0105 and p=0.0006) and OSX (p=0.0105), but a reduced immunolabeling pattern for TRAP (p=0.0056) and RANKL (p=0.033 and 0.004). ST increased the immunolabeling pattern for RUNX2 (p=0.0105), and association with Ral resulted in an increased immunolabeling pattern for OPG (p=0.0034) and OCN (p=0.0024). In summary, ST and Ral administration in aged, estrogen-deficient Wistar female rats is associated with a decrease in bone turnover marker plasma levels, increased activity of cells that promote osteoblastogenesis, and decreased activity of cells that promote osteoclastogenesis; these are correlated with higher aBMD, bone strength, and bone microarchitecture at the femoral neck. The results indicate that strength training and Ral are potential tools to reduce the risk of fractures at clinically relevant sites.
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Affiliation(s)
| | | | | | - Mário Jefferson Quirino Louzada
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas; Faculdade de Medicina Veterinária de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Apoio, Produção e Saúde Animal
| | - Ana Cláudia Stevanato Nakamune
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas; Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
| | - Antonio Hernandes Chaves-Neto
- Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
| | - Ana Cláudia Rossi
- Faculdade de Odontologia de Piracicaba, UNICAMP - Univ de Campinas, Campus de Piracicaba, Departamento de Morfologia
| | - Edilson Ervolino
- Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
| | - Rita Cássia Menegati Dornelles
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas; Faculdade de Odontologia de Araçatuba, UNESP - Univ Estadual Paulista, Campus de Araçatuba, Departamento de Ciências Básicas
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15
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Klein-Nulend J, van Oers RFM, Bakker AD, Bacabac RG. Bone cell mechanosensitivity, estrogen deficiency, and osteoporosis. J Biomech 2014; 48:855-65. [PMID: 25582356 DOI: 10.1016/j.jbiomech.2014.12.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2014] [Indexed: 11/26/2022]
Abstract
Adaptation of bone to mechanical stresses normally produces a bone architecture that combines a proper resistance against failure with a minimal use of material. This adaptive process is governed by mechanosensitive osteocytes that transduce the mechanical signals into chemical responses, i.e. the osteocytes release signaling molecules, which orchestrate the recruitment and activity of bone forming osteoblasts and/or bone resorbing osteoclasts. Computer models have shown that the maintenance of a mechanically-efficient bone architecture depends on the intensity and spatial distribution of the mechanical stimulus as well as on the osteocyte response. Osteoporosis is a condition characterized by a reduced bone mass and a compromized resistance of bone against mechanical loads, which has led us to hypothesize that mechanotransduction by osteocytes is altered in osteoporosis. One of the major causal factors for osteoporosis is the loss of estrogen, the major hormonal regulator of bone metabolism. Loss of estrogen may increase osteocyte-mediated activation of bone remodeling, resulting in impaired bone mass and architecture. In this review we highlight current insights on how osteocytes perceive mechanical stimuli placed on whole bones. Particular emphasis is placed on the role of estrogen in signaling pathway activation by mechanical stimuli, and on computer simulation in combination with cell biology to unravel biological processes contributing to bone strength.
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Affiliation(s)
- Jenneke Klein-Nulend
- Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands.
| | - René F M van Oers
- Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands; Department of Dental Materials Science, ACTA-University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands
| | - Astrid D Bakker
- Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands
| | - Rommel G Bacabac
- Department of Physics, Medical Biophysics Group, University of San Carlos, Cebu City, Philippines
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Vanderschueren D, Laurent MR, Claessens F, Gielen E, Lagerquist MK, Vandenput L, Börjesson AE, Ohlsson C. Sex steroid actions in male bone. Endocr Rev 2014; 35:906-60. [PMID: 25202834 PMCID: PMC4234776 DOI: 10.1210/er.2014-1024] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority.
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Affiliation(s)
- Dirk Vanderschueren
- Clinical and Experimental Endocrinology (D.V.) and Gerontology and Geriatrics (M.R.L., E.G.), Department of Clinical and Experimental Medicine; Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine (M.R.L., F.C.); and Centre for Metabolic Bone Diseases (D.V., M.R.L., E.G.), KU Leuven, B-3000 Leuven, Belgium; and Center for Bone and Arthritis Research (M.K.L., L.V., A.E.B., C.O.), Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, 413 45 Gothenburg, Sweden
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Li L, Chen X, Lv S, Dong M, Zhang L, Tu J, Yang J, Zhang L, Song Y, Xu L, Zou J. Influence of exercise on bone remodeling-related hormones and cytokines in ovariectomized rats: a model of postmenopausal osteoporosis. PLoS One 2014; 9:e112845. [PMID: 25393283 PMCID: PMC4231162 DOI: 10.1371/journal.pone.0112845] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 10/17/2014] [Indexed: 11/18/2022] Open
Abstract
This study aims to explore the effects of exercise on postmenopausal osteoporosis and the mechanisms by which exercise affects bone remodeling. Sixty-three Wistar female rats were randomly divided into five groups: (1) control group, (2) sham-operated group, (3) OVX (Ovariectomy) group, (4) DES-OVX (Diethylstilbestrol-OVX) group, and (5) Ex-OVX (Exercise-OVX) group. The rat osteoporosis model was established through ovariectomy. The Ex-OVX rats were made to run 251.2 meters every day, 6 d/wk for 3 months in a running wheel. Trabecular bone volume (TBV%), total resorption surface (TRS%), trabecular formation surface (TFS%), mineralization rate (MAR), bone cortex mineralization rate (mAR), and osteoid seam width (OSW) were determined by bone histomorphometry. The mRNA and protein levels of interleukin-1β (IL-1β2), interleukin-6 (IL-6), and cyclooxygenase-2 (Cox-2) were determined by in situ hybridization and immunohistochemistry, respectively. Serum levels of estrogen estradiol (E2), calcitonin (CT), osteocalcin (BGP), and parathyroid hormone (PTH) were determined by ELISA assays. The investigation revealed that compared to the control and the sham-operated groups, the OVX group showed significantly lower levels of TBV%, E2, and CT, but much higher levels of TRS%, TFS%, MAR, OSW, BGP, and PTH. The Ex-OVX group showed increased TBV% and serum levels of E2 and CT compared to the OVX group. Ovariectomy also led to a significant increase in IL-1β mRNA and protein levels in the bone marrow and IL-6 and Cox-2 protein levels in tibias. In addition, the Ex-OVX group showed lower levels of IL-1 mRNA and protein, IL-6 mRNA, and Cox-2 mRNA and protein than those in the OVX group. The upshot of the study suggests that exercise can significantly increase bone mass in postmenopausal osteoporosis rat models by inhibiting bone resorption and increasing bone formation, especially in trabecular bones.
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Affiliation(s)
- Lihui Li
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Xi Chen
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- School of Sports Science, Wenzhou Medical University, Wenzhou, China
| | - Shuang Lv
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Miaomiao Dong
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Li Zhang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Jiaheng Tu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Jie Yang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Lingli Zhang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Yinan Song
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Leiting Xu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
- Medical School of Ningbo University, Ningbo, China
| | - Jun Zou
- Scientific Research Department, Shanghai University of Sport, Shanghai, China
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Fernandes Maia BB, Del Carlo RJ, Drummond LR, Gouveia Pelúzio MDC, Osório Silva CH, Quirino Louzada MJ, Quintão Junior JF, Lavorato VN, Soares Ramos RM, Natali AJ. Treinamento em corrida de baixa intensidade: propriedades estruturais e mecânicas da epífise proximal do fêmur de ratas osteopênicas. REVISTA BRASILEIRA DE CIÊNCIAS DO ESPORTE 2014. [DOI: 10.1590/2179-325520143630016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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20
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A rehabilitation exercise program induces severe bone mineral deficits in estrogen-deficient rats after extended disuse. Menopause 2013; 19:1267-76. [PMID: 22713863 DOI: 10.1097/gme.0b013e318255657f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Both estrogen and mechanical loading regulate bone maintenance. However, mechanical overload seems less effective in enhancing bone mineral density (BMD) in estrogen-deficient women. The aim of this study was to determine whether estradiol (E2) influences early-phase bone adaptations to reambulation (REAMB) and/or rehabilitation exercises after hindlimb unloading (HLU) of ovariectomized rats. METHODS Eighty-one 5-month-old female Sprague-Dawley rats were randomized into the following groups: (1) intact controls, (2) ovariectomy (OVX), (3) OVX + E2, (4) OVX + 4 weeks of HLU, (5) OVX + E2 + HLU, (6) OVX + HLU + 2 weeks of quadrupedal REAMB, (7) OVX + E2 + HLU + REAMB, (8) OVX + HLU + REAMB + supplemental climbing, jumping, and balance exercises (EX), or (9) OVX + E2 + HLU + REAMB + EX. Serial dual-energy x-ray absorptiometry scans were performed to track total body bone characteristics throughout the study, and peripheral quantitative computerized tomography was used to determine distal femoral metaphyseal bone mineral characteristics. RESULTS Total body BMD increased by 4% to 8% in all animals receiving supplemental E2, whereas BMD did not change in animals without E2. OVX reduced trabecular BMD at the femoral metaphysis, and HLU exacerbated this loss while also reducing cortical BMD. E2 protected against OVX + HLU-induced bone loss at the femoral metaphysis. Conversely, REAMB did not alter BMD, regardless of estrogen status. In the absence of E2, REAMB + EX resulted in severe bone loss after OVX + HLU, with trabecular BMD and cortical BMD measurements that were 91% and 7% below those of controls, respectively (P ≤ 0.001). However, in the presence of E2, REAMB + EX did not negatively influence bone mineral characteristics. CONCLUSIONS E2 protects against bone loss resulting from combined OVX + HLU of rodents. In the absence of estrogen, exercise induces disadvantageous early-phase bone adaptations after extended disuse.
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Gordon KE, Wald MJ, Schnitzer TJ. Effect of Parathyroid Hormone Combined With Gait Training on Bone Density and Bone Architecture in People With Chronic Spinal Cord Injury. PM R 2013; 5:663-71. [DOI: 10.1016/j.pmrj.2013.03.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 03/14/2013] [Accepted: 03/23/2013] [Indexed: 10/27/2022]
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Swift SN, Baek K, Swift JM, Bloomfield SA. Restriction of dietary energy intake has a greater impact on bone integrity than does restriction of calcium in exercising female rats. J Nutr 2012; 142:1038-45. [PMID: 22513985 DOI: 10.3945/jn.111.153361] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We sought to elucidate the effects of restricting calcium, energy, or food on the skeletal integrity of exercising female rats. Female Sprague-Dawley rats (4 mo old) were randomly assigned to 5 groups (n = 10/group): ad libitum intake of an AIN-93M diet (Research Diets D10012M, Research Diets, Inc.) with no exercise (AL-S) or with exercise (AL-EX) or to 1 of 3 exercising restriction groups [40% restriction of calcium only (CAR-EX), energy only (ER-EX), or food (FR-EX)]. All EX rats were treadmill trained 3 d/wk, 45 min/d for 12 wk at ~60% maximal oxygen consumption. After 12 wk, total body bone mineral content (by DXA) and body mass, but not lean mass, were lower in ER-EX (-17%) and FR-EX rats (-13%) compared with the AL-EX group. CAR-EX had few negative effects on bone geometry (by peripheral quantitative computed tomography) or histomorphometry. However, declines in total volumetric bone mineral density at the proximal tibia metaphysic (PTM) were observed in ER-EX (-6%) and FR-EX (-8%) groups; only FR-EX rats exhibited increased osteoclast surface and decreased mineral apposition rate in PTM cancellous bone. Decrements in serum estradiol, uterine weights, or both in these 2 groups implicate altered estrogen status as contributory. Urine pH declined significantly by 12 wk in all restricted groups, but net acid excretion increased only in CAR-EX rats. These findings, when compared with published data on sedentary rats, suggest that treadmill running exercise may mitigate some, but not all, deleterious effects on bone after chronic energy or food restriction but is more protective during calcium restriction.
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Affiliation(s)
- Sibyl N Swift
- Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
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Kasharafifard S, Hojjati S, Daryanoosh F, Mehrabani D, Almasi-Hashiani A, Vojdani S, Tanideh N, Askarzadeh A, Rasouli O. Reproductive hormonal changes after incremental exercise in female rats. Pak J Biol Sci 2012; 15:403-407. [PMID: 24199472 DOI: 10.3923/pjbs.2012.403.407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Regular physical exercises can affect hormonal system of female athletes. This study evaluated the reproductive hormonal changes after an incremental exercise in female rats. Forty female 2 months old Sprague Dawley rats (200 +/- 5 g) were randomly divided into 4 equal groups including group 1 as control, group 2 undergoing incremental exercise, group 3 receiving supplement soy milk and group 4 undergoing incremental exercise together with a supplement of soy milk. The incremental exercise consisted of running on a flatted treadmill 3 days/weak for 10 weeks. The speed of treadmill gradually increased from 18 to 36 m min(-1) and the duration of each exercise started from 5 min in the first week and reached 8 min in the last week of exercise. The supplemented soy milk was administered for 10 weeks. After 10 weeks, animals were bled and the level of estrogen, progesterone, Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) were determined. The LH level was statistically significant different between groups 1 and 2, 1 and 4, 2 and 3 (p < 0.05) and groups 3 and 4 (p < 0.05). FSH level was statistically significant between groups 1 and 4 (p < 0.05), 3 and 4 (p < 0.05). Regarding the estrogen level, the difference was not significant between the groups. Progesterone level was statistically significant between groups 1 and 4, 2 and 3, 1 and 3 (p < 0.05) and 2 and 4 (p < 0.05). It may be said that changes in the sex hormone are affected by various factors, but what should be considered is the interaction of these hormones. Internal hormonal changes are dependent on the sport history, intensity, duration, level and duration of soy milk supplementation.
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Affiliation(s)
- Somayeh Kasharafifard
- Exercise Physiology Department, Central Branch, Islamic Azad University, Tehran, Iran
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Cheung WH, Chow SKH, Sun MH, Qin L, Leung KS. Low-intensity pulsed ultrasound accelerated callus formation, angiogenesis and callus remodeling in osteoporotic fracture healing. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:231-238. [PMID: 21257088 DOI: 10.1016/j.ultrasmedbio.2010.11.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 11/10/2010] [Accepted: 11/24/2010] [Indexed: 05/30/2023]
Abstract
Osteoporotic fracture is a critical medico-social challenge leading to burdens in health care costs and hospital bed stays. Low-intensity pulsed ultrasound (LIPUS) was reported to accelerate normal fracture; however, its effect on osteoporotic fracture has not been previously addressed. We hypothesize that LIPUS can accelerate osteoporotic fracture healing and up-regulate the expression in the osteogenesis-, remodeling- and angiogenesis-related genes. Ovariectomy-induced osteoporotic fracture rat model was used to investigate the effects of LIPUS. Fractured rats were assigned to LIPUS or control group and healing was assessed by gene expression quantification, radiographic callus morphometry and histomorphometry. In the LIPUS group, Col-1 and bone morphogenetic protein-2 were up-regulated at earlier time points of week 2 to week 4 post-fracture; vascular endothelial growth factor was found to be up-regulated at week 4 to week 8; osteoprotegerin was up-regulated at week 2 post-fracture, followed by the surge of RANKL expression. Callus width and area measurements showed higher callus formation at weeks 2-4 in the LIPUS group and more rapid drop at weeks 6-8. Histomorphometry showed enhanced endochondral ossification in the callus at weeks 2-4, and lower at week 8. We conclude that LIPUS can accelerate osteoporotic fracture healing by enhancing callus formation, angiogenesis and callus remodeling.
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Affiliation(s)
- Wing-Hoi Cheung
- Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
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25
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Treadmill training prevents bone loss by inhibition of PPARγ expression but not promoting of Runx2 expression in ovariectomized rats. Eur J Appl Physiol 2011; 111:1759-67. [DOI: 10.1007/s00421-010-1820-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2010] [Accepted: 12/27/2010] [Indexed: 01/25/2023]
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Bergmann P, Body JJ, Boonen S, Boutsen Y, Devogelaer JP, Goemaere S, Kaufman J, Reginster JY, Rozenberg S. Loading and skeletal development and maintenance. J Osteoporos 2010; 2011:786752. [PMID: 21209784 PMCID: PMC3010667 DOI: 10.4061/2011/786752] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 11/06/2010] [Indexed: 12/12/2022] Open
Abstract
Mechanical loading is a major regulator of bone mass and geometry. The osteocytes network is considered the main sensor of loads, through the shear stress generated by strain induced fluid flow in the lacuno-canalicular system. Intracellular transduction implies several kinases and phosphorylation of the estrogen receptor. Several extra-cellular mediators, among which NO and prostaglandins are transducing the signal to the effector cells. Disuse results in osteocytes apoptosis and rapid imbalanced bone resorption, leading to severe osteoporosis. Exercising during growth increases peak bone mass, and could be beneficial with regards to osteoporosis later in life, but the gain could be lost if training is abandoned. Exercise programs in adults and seniors have barely significant effects on bone mass and geometry at least at short term. There are few data on a possible additive effect of exercise and drugs in osteoporosis treatment, but disuse could decrease drugs action. Exercise programs proposed for bone health are tedious and compliance is usually low. The most practical advice for patients is to walk a minimum of 30 to 60 minutes per day. Other exercises like swimming or cycling have less effect on bone, but could reduce fracture risk indirectly by maintaining muscle mass and force.
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Affiliation(s)
- P. Bergmann
- Department of Nuclear Medicine, Laboratory of Clinical Chemistry and Experimental Medicine, CHU Brugmann, Université Libre de Bruxelles, 4 Pl. Van Gehuchten, 1020 Brussels, Belgium,*P. Bergmann:
| | - J. J. Body
- Department of Medicine, CHU Brugmann, Université Libre de Bruxelles, 1020 Brussels, Belgium
| | - S. Boonen
- Division of Gerontology and Geriatrics, Center for Musculoskeletal Research, Department of Experimental Medicine, Catholic Leuven University, 3000 Leuven, Belgium
| | - Y. Boutsen
- Department of Rheumatology, Mont-Godinne University Hospital, Université Catholique de Louvain, 1200 Brussels, Belgium
| | - J. P. Devogelaer
- Rheumatology Unit, Saint-Luc University Hospital, Université Catholique de Louvain, 1200 Brussels, Belgium
| | - S. Goemaere
- Unit for Osteoporosis and Metabolic Bone Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - J. Kaufman
- Unit for Osteoporosis and Metabolic Bone Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - J. Y. Reginster
- Department of Public Health Sciences, University of Liège, 4000 Liège, Belgium
| | - S. Rozenberg
- Department of Gynaecology-Obstetrics, Free University of Brussels, 1090 Brussels, Belgium
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Chang TK, Huang CH, Huang CH, Chen HC, Cheng CK. The influence of long-term treadmill exercise on bone mass and articular cartilage in ovariectomized rats. BMC Musculoskelet Disord 2010; 11:185. [PMID: 20727126 PMCID: PMC2936345 DOI: 10.1186/1471-2474-11-185] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 08/20/2010] [Indexed: 11/18/2022] Open
Abstract
Background Loss of bone quality and deterioration of articular cartilage are commonly seen after menopause. While exercise may protect against tissue degeneration, a clear link has yet to be established. The aim of the present study is to investigate the influence of long-term treadmill exercise on changes in bone mass and articular cartilage in ovariectomized rats. Methods Sixty female Sprague-Dawley rats were randomly assigned to 4 groups: ovariectomized (OVX), ovariectomized plus treadmill exercise (OVX-RUN), treadmill exercise alone (RUN), and control (CON) groups. After 36 weeks, the following variables were compared among the 4 groups. Bone mass was evaluated by trabecular bone volume and bone mineral density (BMD). Articular cartilage in the knee joints was evaluated by histology analysis and a modified Mankin score. Results Rats in the ovariectomized groups (OVX and OVX-RUN) had significantly lower BMD and bone mass than the non-ovariectomized rats (CON and RUN), indicating that exercise did little to preserve bone mass. However, the sedentary OVX group had a significantly worse modified Mankin score (7.7 ± 1.4) than the OVX-RUN group (4.8 ± 1.0), whose scores did not differ significantly from the other 2 non-operated groups. The articular cartilage in the sedentary OVX rats was relatively thinner, hypocellular, and had more clefts than in the other 3 groups. Conclusion This study suggests that long-term exercise protects articular cartilage in OVX rats but does not retard the loss of bone mass seen in after menopause.
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Affiliation(s)
- Ting-Kuo Chang
- Institute of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan
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Hewitt SC, Kissling GE, Fieselman KE, Jayes FL, Gerrish KE, Korach KS. Biological and biochemical consequences of global deletion of exon 3 from the ER alpha gene. FASEB J 2010; 24:4660-7. [PMID: 20667977 DOI: 10.1096/fj.10-163428] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To address issues resulting from α estrogen receptor-knockout (αERKO) residual N-terminal truncated estrogen receptor α, and to allow tissue-selective deletion of ERα, we generated loxP-flanked exon 3 mice. Initial characterization of global sox2 cre-derived exon 3-deleted Ex3αERKO mice indicated no ERα protein in uterine tissue and recapitulation of previously described female phenotypes, confirming successful ablation of ERα. Body weights of Ex3αERKO female mice were 1.4-fold higher than wild-tupe (WT) females and comparable to WT males. Microarray indicated the Ex3αERKO uterus is free of residual estrogen responses. RT-PCR showed Nr4a1 is increased 41-fold by estrogen in WT and 7.4-fold in αERKO, and not increased in Ex3αERKO. Nr4a1, Cdkn1a, and c-fos transcripts were evaluated in WT and Ex3αERKO mice following estrogen, IGF1, or EGF injections. All 3 were increased by all treatments in WT. None were increased by estrogen in Ex3αERKO. Nr4a1 increased 24.5- and 14.7-fold, Cdkn1a increased 14.2- and 12.3-fold, and c-fos increased 20.9-fold and 16.2-fold after IGF1 and EGF treatments, respectively, in the Ex3αERKO mice, confirming that growth factor regulation is independent of ERα. Our Ex3α ERα model will be useful in studies of complete or selective ablation of ERα in target tissues.
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Affiliation(s)
- Sylvia C Hewitt
- Laboratory of Reproductive and Developmental Toxicology, National Institutes of Health, Research Triangle Park, North Carolina, USA.
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29
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Hewitt SC, Kissling GE, Fieselman KE, Jayes FL, Gerrish KE, Korach KS. Biological and biochemical consequences of global deletion of exon 3 from the ERα gene. FASEB J 2010. [DOI: 10.1096/fj.10.163428] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sylvia C. Hewitt
- Laboratory of Reproductive and Developmental ToxicologyNational Institutes of Health, Research Triangle Park North Carolina USA
| | - Grace E. Kissling
- Biostatistics BranchNational Institutes of Health, Research Triangle Park North Carolina USA
| | - Karen E. Fieselman
- Laboratory of Reproductive and Developmental ToxicologyNational Institutes of Health, Research Triangle Park North Carolina USA
| | - Friederike L. Jayes
- Laboratory of Reproductive and Developmental ToxicologyNational Institutes of Health, Research Triangle Park North Carolina USA
| | - Kevin E. Gerrish
- Microarray Core National Institute of Environmental Health SciencesNational Institutes of Health, Research Triangle Park North Carolina USA
| | - Kenneth S. Korach
- Laboratory of Reproductive and Developmental ToxicologyNational Institutes of Health, Research Triangle Park North Carolina USA
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Wehrli FW, Rajapakse CS, Magland JF, Snyder PJ. Mechanical implications of estrogen supplementation in early postmenopausal women. J Bone Miner Res 2010; 25:1406-14. [PMID: 20200948 PMCID: PMC3153138 DOI: 10.1002/jbmr.33] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Whereas the structural implications of drug intervention are well established, there are few data on the possible mechanical consequences of treatment. In this work we examined the changes in elastic and shear moduli (EM and SM) in a region of trabecular bone in the distal radius and distal tibia of early postmenopausal women on the basis of MRI-based micro-finite-element (microFE) analysis. Whole-section axial stiffness (AS) encompassing both trabecular and cortical compartments was evaluated as well. The study was conducted on previously acquired high-resolution images at the two anatomic sites. Images were processed to yield a 3D voxel array of bone-volume fraction (BVF), which was converted to a microFE model of hexahedral elements in which tissue modulus was set proportional to voxel BVF. The study comprised 65 early postmenopausal women (age range 45 to 55 years), of whom 32 had chosen estrogen supplementation (estradiol group); the remainder had not (control group). Subjects had been scanned at baseline and 12 and 24 months thereafter. At the distal tibia, EM and SM were reduced by 2.9% to 5.5% in the control group (p < .05 to <.005), but there was no change in the estradiol subjects. AS decreased 3.9% (4.0%) in controls (p < .005) and increased by 5.8% (6.2%) in estradiol group subjects (p < .05) at 12 (24) months. At the distal radius, EM and SM changes from baseline were not significant, but at both time points AS was increased in estradiol group subjects and decreased in controls (p < .005 to <.05), albeit by a smaller margin than at the tibia. EM and SM were strongly correlated with BV/TV (r(2) = 0.44 to 0.92) as well as with topologic parameters expressing the ratio of plates to rods (r(2) = 0.45 to 0.82), jointly explaining up to 96% of the variation in the mechanical parameters. Finally, baseline AS was strongly correlated between the two anatomic sites (r(2) = 0.58), suggesting that intersubject variations in the bone's mechanical competence follows similar mechanisms. In conclusion, the results demonstrate that micro-MRI-based microFE models are suited for the study of the mechanical implications of antiresorptive treatment. The data further highlight the anabolic effect of short-term estrogen supplementation.
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Affiliation(s)
- Felix W Wehrli
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Hawkins J, Cifuentes M, Pleshko NL, Ambia-Sobhan H, Shapses SA. Energy restriction is associated with lower bone mineral density of the tibia and femur in lean but not obese female rats. J Nutr 2010; 140:31-7. [PMID: 19923391 PMCID: PMC2793120 DOI: 10.3945/jn.109.111450] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Energy restriction decreases bone mineral density (BMD), and epidemiological studies suggest that the risk of weight loss-induced bone loss is greater in lean than in heavier individuals. Our goal in this study was to determine how bone density and geometry respond to energy restriction in mature obese rats compared with lean rats. At 6 mo of age, 36 diet-induced obese and lean female Sprague-Dawley rats were allocated to control (CTL; ad libitum; n = 18) and energy-restricted (EnR; 40% restriction; n = 18) diets. After 10 wk of dietary intervention, obese EnR rats lost more weight (-91 +/- 34 g) than lean EnR rats(-61 +/- 14 g) (P < 0.02), [corrected] whereas body weight did not change significantly in the 2 CTL groups (14 +/- 23 g). Only the lean EnR (and not obese EnR) rats showed lower BMD compared with CTL rats at the tibia, distal, and proximal femur and femoral neck, and trabecular bone volume (P < 0.05). Serum estradiol declined in lean EnR rats compared with baseline (P < 0.05) but not in the obese EnR rats. In addition, the final serum 25-hydroxyvitamin D (25OHD) concentration was higher (P < 0.05) in obese than in lean EnR rats. Serum parathyroid hormone decreased (P < 0.05) from baseline to final in lean and obese CTL, but not EnR rats. These data support the hypothesis that energy restriction in lean rats compared with obese rats is more detrimental to bone, and it is possible that the greater decline in estrogen and lower levels of 25OHD contribute to this effect.
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Affiliation(s)
- Jaleah Hawkins
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ; Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile; Research Division, Hospital for Special Surgery, New York, NY 10021
| | - Mariana Cifuentes
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ; Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile; Research Division, Hospital for Special Surgery, New York, NY 10021
| | - Nancy L. Pleshko
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ; Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile; Research Division, Hospital for Special Surgery, New York, NY 10021
| | - Hasina Ambia-Sobhan
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ; Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile; Research Division, Hospital for Special Surgery, New York, NY 10021
| | - Sue A. Shapses
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ; Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, Santiago, Chile; Research Division, Hospital for Special Surgery, New York, NY 10021,To whom correspondence should be addressed. E-mail:
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Britz HM, Thomas CDL, Clement JG, Cooper DML. The relation of femoral osteon geometry to age, sex, height and weight. Bone 2009; 45:77-83. [PMID: 19303955 DOI: 10.1016/j.bone.2009.03.654] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 03/04/2009] [Accepted: 03/04/2009] [Indexed: 02/01/2023]
Abstract
As computational modeling becomes an increasingly common tool for probing the regulation of bone remodeling, the need for experimental data to refine and validate such models also grows. For example, van Oers et al. (R.F. van Oers, R. Ruimerman, B. van Rietbergen, P.A. Hilbers, R. Huiskes, Relating osteon diameter to strain. Bone 2008;43: 476-482.) recently described a mechanism by which osteon size may be regulated (inversely) by strain. Empirical data supporting this relation, particularly in humans, are sparse. Therefore, we sought to determine if there is a link between body weight (the only measure related to loading available for a cadaveric population) and osteon geometry in human bone. We hypothesized that after controlling for age, sex and height, weight would be inversely related to femoral osteon size (area, On.Ar; diameter, On.Dm). Secondarily we sought to describe the relation between osteon circularity (On.Cr) and these parameters. Osteons (n=12,690) were mapped within microradiographs of femoral mid-diaphyseal specimens (n=88; 45 male, 43 female; 17-97 yrs). Univariate analysis of covariance was conducted (n=87; 1 outlier) with sex as a fixed factor and height, weight and log-transformed age as covariates. Weight was negatively related to On.Ar and On.Dm (p=0.006 and p=0.004, respectively). Age was significantly related to osteon and, it was also significantly related to circularity (all p<0.001). This relation was negative for On.Ar and On.Dm and positive for On.Cr (increasing circularity with age). On.Ar and On.Dm were found to be significantly different between the sexes (p=0.021 and p=0.019, respectively), with females having smaller osteons. No relation between sex and On.Cr was detected (p=0.449). Height was not significantly related to any of the geometric parameters. Partial eta-squared values revealed that age accounted for the largest proportion (On.Ar: 28%, On.Dm: 18%, On.Cr: 30%), weight accounted for the second largest (On.Ar: 9%, On.Dm: 10%) and sex accounted for the smallest proportion (On.Ar: 6%, On.Dm: 7%) of the variance in geometry. While previous studies have reported relations between osteon size and sex/age, we believe that our findings are the first to demonstrate a link with weight. We believe that this negative relation with weight is most probably mechanical in nature; however, alternative (endocrine) links between bone and adipose tissue cannot be ruled out by our design.
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Affiliation(s)
- Hayley M Britz
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Hydock DS, Iwaniec UT, Turner RT, Lien CY, Jensen BT, Parry TL, Schneider CM, Hayward R. Effects of voluntary wheel running on goserelin acetate-induced bone degeneration. PATHOPHYSIOLOGY 2008; 15:253-9. [PMID: 19041803 DOI: 10.1016/j.pathophys.2008.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 09/10/2008] [Accepted: 10/02/2008] [Indexed: 11/28/2022] Open
Abstract
A common treatment option for many breast and prostate cancer patients is the use of a luteinizing hormone-releasing hormone agonist such as goserelin acetate (GA) which reduces sex hormone levels. This treatment, however, is associated with bone degeneration, and exercise has been suggested as a means of preventing this side effect. Little is known about the effects of low intensity, low volume exercise on GA-induced bone loss. The purpose of this study, therefore, was to investigate the effects of voluntary wheel running on bone architecture in growing male (M) and female (F) rats receiving GA treatment. Rats received an 8-week GA treatment or placebo (CON) and were either housed in cages equipped with voluntary running wheels (WR) or remained sedentary (SED) in standard cages throughout the experimental period. Following treatments, tibiae were excised and analyzed for cortical bone (cross-sectional volume, cortical volume, marrow volume, cortical thickness) and cancellous bone (bone volume/total volume, trabecular number, trabecular thickness, trabecular spacing) using micro-computed tomography. Treatment with GA resulted in a significant reduction in running wheel distances in both sexes throughout the study period (P<0.05). GA treatment had no effect on cortical bone architecture in neither sex (P>0.05). Cancellous bone degeneration, however, was observed in M and F SED+GA (P<0.05). No significant differences were observed in M WR+GA animals in bone volume/total volume, trabecular number and trabecular spacing when compared to M SED+CON (P>0.05). In F WR+GA, trabecular thickness did not differ from that of F SED+CON (P>0.05), and trabecular spacing was found to be significantly lower than F SED+GA (P<0.05). The current report indicates that 8 weeks of GA treatment promotes cancellous bone degeneration, and voluntary wheel running provides no clear osteoprotection in growing male and female rats.
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Affiliation(s)
- David S Hydock
- School of Sport and Exercise Science and the Rocky Mountain Cancer Rehabilitation Institute, University of Northern Colorado, Greeley, CO, United States
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Martyn-St James M, Carroll S. Meta-analysis of walking for preservation of bone mineral density in postmenopausal women. Bone 2008; 43:521-31. [PMID: 18602880 DOI: 10.1016/j.bone.2008.05.012] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2007] [Revised: 04/26/2008] [Accepted: 05/17/2008] [Indexed: 11/27/2022]
Abstract
Whilst exercise is recommended for optimum bone health in adult women, there are few systematic reviews of the efficacy of walking as singular exercise therapy for postmenopausal bone loss. The aim of this study was to assess the effects of prescribed walking programmes on bone mineral density (BMD) at the hip and spine in postmenopausal women and to determine if effects are modified by variations in protocol design. We undertook a systematic review and meta-analysis of randomised (RCTs) and non-randomised controlled trials. Electronic bibliographic databases, key journals and reference lists of reviews and articles were searched to identify studies for inclusion. Randomised and non-randomised controlled trials assessing the effects of walking on lumbar spine, femoral neck and total hip BMD, measured by radiographic techniques, among sedentary postmenopausal women were eligible for inclusion. Two independent reviewers assessed studies for eligibility. Reported absolute BMD outcomes were combined in the analysis. Weighted mean differences (WMD) were calculated using a fixed and random-effects models. Heterogeneity among trials was examined using the Q statistic and I2 methods. Potential publication bias was assessed through funnel plot inspection. Assessment of trial quality was also performed using the widely used instrument devised by Jadad et al. [Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJM, Gavaghan DJ, et al. Assessing the quality of reports of randomized clinical trials: Is blinding necessary? Cont Clin Trials 1996; 17:1-12]. Eight trials were eligible for inclusion. Treatment duration ranged from 6 to 24 months. All eight trials reported BMD data at the lumbar spine following walking interventions among postmenopausal women. Meta-analysis showed no significant change in BMD at this site [WMD (fixed-effect) 0.007 g/cm2 95% CI (-0.001 to 0.016); P=0.09)]. BMD data at the femoral neck were available from five trials among postmenopausal women. Results were inconsistent (I2=51.4%) in showing a positive effect of walking on BMD at this site [WMD (random-effects) 0.014 g/cm2 95% CI (0.000 to 0.028); P=0.05). Insufficient data were available for meta-analysis of the total hip site. Funnel plots showed some asymmetry for negative lumbar spine BMD outcomes. Trial quality scores ranged from 0 to 3 from the Jadad scale of 0 to 5. We conclude that regular walking has no significant effect on preservation of BMD at the spine in postmenopausal women, whilst significant positive effects at femoral neck are evident. However, diverse methodological and reporting discrepancies are apparent in the published trials on which these conclusions are based. Other forms of exercise that provide greater targeted skeletal loading may be required to preserve bone mineral density in this population.
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Affiliation(s)
- Marrissa Martyn-St James
- Carnegie Faculty of Sport and Education, Leeds Metropolitan University, Room 202, Fairfax Hall, Headingley Campus, Leeds LS6 3QT, UK.
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Forwood MR. Physical activity and bone development during childhood: insights from animal models. J Appl Physiol (1985) 2008; 105:334-41. [DOI: 10.1152/japplphysiol.00040.2008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Animal studies illustrate greater structural and material adaptations of growing bone to exercise than in adult bones but do not define effective training regimes to optimize bone strength in children. Controlled loading studies in turkey, rat, or mouse bones have revealed mechanisms of mechanotransduction and loading characteristics that optimize the modeling response to applied strains. Insights from these models reveal that static loads do not play a role in mechanotransduction and that bone formation is threshold driven and dependent on strain rate, amplitude, and partitioning of the load. That is, only a few cycles of loading are required at any time to elicit an adaptive response, and distributed bouts of loading, incorporating rest periods, are more osteogenic than single sessions of long duration. These parameters of loading have been translated into feasible public health interventions that exploit the insights gained from animal experiments to achieve adaptive responses in children and adolescents. Studies manipulating estrogen receptors (ER) in mice also demonstrate that skeletal sensitivity to loading during the peripubertal period is due to a direct regulation of mechanotransduction pathways by ER, and not just a simple enhancement of cell activity already marshaled by the hypothalamic-pituitary axis. Unfortunately, because the rate and timing of growth in small animals are completely different from those in humans, these models can be poor tools to elucidate periods during growth in youths, during which the skeleton is more sensitive to loading. However, there are insights from studies of human growth that can improve the interpretation of data from such studies of growth and development in animals.
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Dai R, Ma Y, Sheng Z, Jin Y, Zhang Y, Fang L, Fan H, Liao E. Effects of genistein on vertebral trabecular bone microstructure, bone mineral density, microcracks, osteocyte density, and bone strength in ovariectomized rats. J Bone Miner Metab 2008; 26:342-9. [PMID: 18600400 DOI: 10.1007/s00774-007-0830-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2007] [Accepted: 11/05/2007] [Indexed: 10/21/2022]
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 17beta-estradiol (EST, 10 microg x kg(-1) x day(-1)), and GEN (5 mg x kg(-1) x day(-1)). At 15 weeks postoperation, the compressive test was performed on the L5 vertebral body; additionally, microcomputed tomography (micro-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.
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Affiliation(s)
- Ruchun Dai
- Institute of Metabolism and Endocrinology, Second Xiang-Ya Hospital, Central South University, 139 Renmin-Zhong Rd, Changsha, 410011 Hunan, China
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