Faculty Opinions recommendation of Biomechanical properties of the mid-shaft femur in middle-aged hypophysectomized rats as assessed by bending test.

The effects of treadmill interval training (IT) and free fall exercise were evaluated on bone parameters including osteocyte related characteristics. Thirty-eight 4-month-old male Wistar rats were randomly divided into a control group (C) and exercise groups: IT, 10 free fall impacts/day with a 10s (FF10) or 20s interval between drops (FF20), 5 days/week, for 9 weeks. We assessed: BMD, microarchitecture by µCT, mechanical strength by a three-point bending test, density and occupancy of the osteocyte lacunae by toluidine blue staining, osteocalcin and NTx systemic levels by ELISA, and bone tissue Sost mRNA expression by RT-PCR. NTx levels were significantly lower in exercise groups as compared to C. In exercise groups Sost mRNA expression was significantly lower than in C. Tb.N was significantly higher for IT and FF20 compared to C; Tb.Sp was significantly lower in FF10 compared to C. Both IT and FF20 were associated with higher tibial lacunar density as compared to FF10. Compared to FF10, IT fat mass was lower, while tibial osteocyte lacunae occupancy and systemic osteocalcin level were higher. All exercise modes were efficient in reducing bone resorption. Both IT and FF impact with appropriate recovery periods might be beneficial for bone health and osteocyte related characteristics. Novelty bullets: • Interval training is beneficial for bone mineral density • Exercises decreased both bone resorption and inhibition of bone formation (sost mRNA) • Longer interval recovery time favors osteocyte lacunae density

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Effects of treadmill with different intensities on bone quality and muscle properties in adult rats

BioMedical Engineering OnLine ◽

10.1186/s12938-019-0728-0 ◽

2019 ◽

Vol 18 (1) ◽

Cited By ~ 1

Author(s):

Zhehao Liu ◽

Jiazi Gao ◽

He Gong

Keyword(s):

Cortical Bone ◽

Soleus Muscle ◽

Adult Male ◽

Biomechanical Properties ◽

Treadmill Running ◽

Male Rats ◽

Bending Test ◽

Long Bone ◽

Nanoindentation Test ◽

Adult Rats

Abstract Background Bone is a dynamically hierarchical material that can be divided into length scales of several orders of magnitude. Exercise can cause bone deformation, which in turn affects bone mass and structure. This study aimed to study the effects of treadmill running with different intensities on the long bone integrity and muscle biomechanical properties of adult male rats. Methods Forty-eight 5-month-old male SD rats were randomly divided into 4 groups: i.e., sedentary group (SED), exercise with speed of 12 m/min group (EX12), 16 m/min group (EX16), and 20 m/min group (EX20). The exercise was carried out for 30 min every day, 5 days a week for 4 weeks. The femurs were examined using three-point bending test, microcomputer tomography scanning and nanoindentation test; the soleus muscle was dissected for tensile test; ALP and TRACP concentrations were measured by serum analysis. Results The failure load was significantly increased by the EX12 group, whereas the elastic modulus was not significantly changed. The microstructure and mineral densities of the trabecular and cortical bone were significantly improved by the EX12 group. The mechanical properties of the soleus muscle were significantly increased by treadmill exercise. Bone formation showed significant increase by the EX12 group. Statistically higher nanomechanical properties of cortical bone were detected in the EX12 group. Conclusion The speed of 12 m/min resulted in significant changes in the microstructure and biomechanical properties of bone; besides, it significantly increased the ultimate load of the soleus muscle. The different intensities of treadmill running in this study provide an experimental basis for the selection of exercise intensity for adult male rats.

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Properties of biocomposite on the “bone-tocarbon nano implant” border

MATEC Web of Conferences ◽

10.1051/matecconf/201822603010 ◽

2018 ◽

Vol 226 ◽

pp. 03010

Author(s):

George Sh. Golubev ◽

Michael B. Rodin ◽

Vladimir A. Irkha

Keyword(s):

Bone Conduction ◽

Biomechanical Properties ◽

Clinical Results ◽

The Body ◽

Bending Test ◽

Wedge Osteotomy ◽

Bone Block ◽

P Value ◽

Test Field ◽

White Rats

Novice carbon nanostructural material was investigated to estimate its integration to the bone tissue. Wedge osteotomy of a femur bone performed in experimental circumstance on 26 white rats (control=6, experiment=21). Wedge-shaped (h=4 mm, r=3 mm, α=12) implants were crafted from carbon nano-structural material and used to fill bone’s defect. Rats withdrove from the experiment in 3 months. Mechanical properties of the “bone-wedge-bone” block evaluated by the 3-point bending test. Field emission scanning electron microscope used to investigate biocomposite at the bone-to-implant border. The microelements distribution in the samples measured with energy dispersive X-ray analysis. Biomechanical properties of bone-to-implant biocomposite depend on clinical features of consolidation. Anyway, the toughness (T) of bone-to-implant zone is worse than bone-to-bone regenerate significantly (Tcontr = 56.97 MPa, Texp = 47.68 Mpa, Welsh p-value = 2.689e-07). No Ca, or P reveals in the body of implants. The quality and the thickness of the biocomposite on the bone-to-implant border predetermine clinical results of bone substitution. The absence of microelements inside the body of implants confirms that the implant structure is too subtle. Increasing porosity of material and creation of transverse channels can improve bone conduction and scaffold quality of carbon nano-implants.

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Rapamycin Alleviates Cancellous Bone Loss and Cortical Bone Porosity in Ovariectomized Mice but Not Overall Biomechanical Performance

10.21203/rs.3.rs-895657/v1 ◽

2021 ◽

Author(s):

Ruoyao Li ◽

Junhao Liu ◽

Zhiping Huang ◽

Xiuhua Wu ◽

Zhou Yang ◽

...

Keyword(s):

Bone Loss ◽

Cortical Bone ◽

Cancellous Bone ◽

Sham Group ◽

Biomechanical Properties ◽

Bending Test ◽

Tartrate Resistant Acid Phosphatase ◽

Long Bones ◽

Ovariectomized Mice ◽

Vascular Canal

Abstract Background: Recent studies have shown that rapamycin (Rapa) rescues cancellous bone loss of osteoporosis models, but its effects on cortical bone and the biomechanical properties remain uncertain. This study was aimed to determine whether rapamycin improve the quality of long bones in ovariectomy (OVX)-induced osteoporosis.Methods: Thirty female C57BL/6J mice were randomly divided into Sham, OVX and OVX+Rapa group. Mice in the OVX+Rapa group were injected intraperitoneally with 1.5 mg/kg rapamycin daily after ovariectomy. After 12 weeks, the microstructures of femurs and the vascular canal porosity tibiae were analyzed by micro-CT. The compressive stiffness of the distal femurs was calculated with the micro-finite element method, and the bending strength of the tibiae was evaluated with a three-point bending test. Western blot of LC3, P62 was used to assess autophagy activity of bone. The number of osteoclasts was quantified by tartrate-resistant acid phosphatase (TRAP) staining. ELISA detected the concentration of bone-specific alkaline phosphatase (BALP) in serum.Results: OVX led to a decrease in cross-sectional areas of the mid-diaphyses and distal femoral cortical bones, increasing the cortical bone vascular canal porosity from 1.42% to 4.79%. The rapamycin reduced cancellous bone loss and decreased cortical bone vascular canal porosity by 3.9%, but further reduced the thickness of the distal femoral cortical bone by 16.7%, with no significant effect on the cortical bone in the mid-diaphyses. Compared to the Sham group, OVX mice showed a decrease in distal femoral stiffness to 6497 N/mm and a decrease in tibial maximum load to 6.08 N, while rapamycin intervention did not significantly improve the decreased biomechanical properties. Moreover, rapamycin remarkably reduced the TRAP-positive osteoclasts and the concentration of serum BALP by 80.6% and 30.8%, respectively. Autophagy was activated in the OVX group compared with the sham group.Conclusions: This study has demonstrated that rapamycin ameliorates cancellous bone loss and cortical bone porosity in ovariectomized mice but partly reduces the size of cortical bone, while has no effect on improving the biomechanical performance. Additionally, the present study also proved that OVX led to both cancellous and cortical bone loss, with attenuated biomechanical properties of long bones.

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Combination of Weight-Bearing Training and Anti-MSTN Polyclonal Antibody Improve Bone Quality In Rats

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2015-0337 ◽

2016 ◽

Vol 26 (6) ◽

pp. 516-524 ◽

Cited By ~ 8

Author(s):

Liang Tang ◽

Xiaohang Gao ◽

Xiaoying Yang ◽

Didi Zhang ◽

Xiaojun Zhang ◽

...

Keyword(s):

Elastic Modulus ◽

Bone Formation ◽

Energy Absorption ◽

Polyclonal Antibody ◽

Bone Health ◽

Weight Bearing ◽

Biomechanical Properties ◽

Bending Test ◽

Trabecular Thickness ◽

Positive Effect

Weight-bearing exercise is beneficial to bone health. Myostatin (MSTN) deficiency has a positive effect on bone formation. We wondered if a combination of weight-bearing training and polyclonal antibody for MSTN (MsAb) would augment bone formation to a greater degree than single treatment. In this study, rats were randomly assigned to four groups: Control, weight-bearing training (WT), MsAb, and WT+MsAb. The trained rats ran at 15 m/min bearing with 35% of their body weight, 40 min/day (2 min of running followed by 2 min of rest), 6 days/week, for 8 weeks. The rats with MsAb were injected once a week with MsAb for 8 weeks. MicroCT analysis showed that compared with the MsAb group, WT+MsAb significantly enhanced cortical bone mineral density (BMD) (p < .01), bone volume over total volume (BV/TV) (p < .01), trabecular thickness (p < .05), and reduced trabecular separation (Tb.Sp) (p < .01). Compared with the WT group, WT+MsAb significantly increased trabecular BMD (p < .05), BV/TV (p < .05), and decreased Tb.Sp (p < .05). Three-point bending test demonstrated that MsAb failed to improve bone biomechanical properties (p > .05), weight-bearing training significantly increased energy absorption (p < .05) and elastic modulus (p < .05). However, when they combined, biomechanical properties including maximum load (p < .05), stiffness (p < .05), elastic modulus (p < .01) and energy absorption (p < .01) were all significantly enhanced. In conclusion, the combination of weight-bearing training and MsAb have a greater positive effect on bone than treatment with either MsAb or weight-bearing training alone, suggesting that resistance training in combination with MSTN antagonists could be an effective approach for improving bone health and reducing osteoporosis risk.

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Rapamycin Alleviates Cancellous Bone Loss and Cortical Bone Porosity In Ovariectomized Mice But Not Overall Biomechanical Performance

10.21203/rs.3.rs-895657/v2 ◽

2021 ◽

Author(s):

Ruoyao Li ◽

Junhao Liu ◽

Zhiping Huang ◽

Xiuhua Wu ◽

Qingan Zhu

Keyword(s):

Bone Loss ◽

Cortical Bone ◽

Cancellous Bone ◽

Sham Group ◽

Biomechanical Properties ◽

Bending Test ◽

Tartrate Resistant Acid Phosphatase ◽

Long Bones ◽

Ovariectomized Mice ◽

Vascular Canal

Abstract Background: Recent studies have shown that rapamycin (Rapa) rescues cancellous bone loss of osteoporosis models, but its effects on cortical bone and the biomechanical properties remain uncertain. This study was aimed to determine whether rapamycin improve the quality of long bones in ovariectomy (OVX)-induced osteoporosis.Methods: Thirty female C57BL/6J mice were randomly divided into Sham, OVX and OVX+Rapa group. Mice in the OVX+Rapa group were injected intraperitoneally with 1.5 mg/kg rapamycin daily after ovariectomy. After 12 weeks, the microstructures of femurs and the vascular canal porosity tibiae were analyzed by micro-CT. The compressive stiffness of the distal femurs was calculated with the micro-finite element method, and the bending strength of the tibiae was evaluated with a three-point bending test. Western blot of LC3, P62 was used to assess autophagy activity of bone. The number of osteoclasts was quantified by tartrate-resistant acid phosphatase (TRAP) staining. ELISA detected the concentration of bone-specific alkaline phosphatase (BALP) in serum.Results: OVX led to a decrease in cross-sectional areas of the mid-diaphyses and distal femoral cortical bones, increasing the cortical bone vascular canal porosity from 1.42% to 4.79%. The rapamycin reduced cancellous bone loss and decreased cortical bone vascular canal porosity by 3.9%, but further reduced the thickness of the distal femoral cortical bone by 16.7%, with no significant effect on the cortical bone in the mid-diaphyses. Compared to the Sham group, OVX mice showed a decrease in distal femoral stiffness to 6497 N/mm and a decrease in tibial maximum load to 6.08 N, while rapamycin intervention did not significantly improve the decreased biomechanical properties. Moreover, rapamycin remarkably reduced the TRAP-positive osteoclasts and the concentration of serum BALP by 80.6% and 30.8%, respectively. Autophagy was activated in the OVX group compared with the sham group.Conclusions: This study has demonstrated that rapamycin ameliorates cancellous bone loss and cortical bone porosity in ovariectomized mice but partly reduces the size of cortical bone, while has no effect on improving the biomechanical performance. Additionally, the present study also proved that OVX led to both cancellous and cortical bone loss, with attenuated biomechanical properties of long bones.

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Evaluation of the effects of LLLT on biomechanical properties of tibial diaphysis in two rat models of experimental osteoporosis by a three point bending test

Lasers in Medical Science ◽

10.1007/s10103-014-1706-1 ◽

2015 ◽

Vol 30 (3) ◽

pp. 1117-1125 ◽

Cited By ~ 17

Author(s):

Mohammadjavad Fridoni ◽

Reza Masteri Farahani ◽

Hossein Nejati ◽

Maryam Salimi ◽

Seyed Masih Gharavi ◽

...

Keyword(s):

Biomechanical Properties ◽

Bending Test ◽

Rat Models ◽

Three Point Bending ◽

Tibial Diaphysis ◽

Experimental Osteoporosis

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Protective Effect of Chokeberry (Aronia melanocarpa L.) Extract Against Cadmium Impact on the Biomechanical Properties of the Femur: A Study in a Rat Model of Low and Moderate Lifetime Women Exposure to this Heavy Metal

10.20944/preprints201705.0120.v1 ◽

2017 ◽

Author(s):

Małgorzata M. Brzóska ◽

Alicja Roszczenko ◽

Joanna Rogalska ◽

Małgorzata Gałażyn-Sidorczuk ◽

Magdalena Mężyńska

Keyword(s):

Bone Tissue ◽

Chronic Exposure ◽

Biomechanical Properties ◽

Female Rats ◽

Bone Collagen ◽

Bending Test ◽

Three Point Bending ◽

Low Level ◽

Aronia Melanocarpa ◽

Natural Agent

The hypothesis that consumption of Aronia melanocarpa berries (chokeberries) extract, recently reported by us to improve bone metabolism in female rats at low-level and moderate chronic exposure to cadmium (1 and 5 mg Cd/kg diet for up to 24 months), may increase the bone resistance to fracture was investigated. Biomechanical properties of the neck (bending test with vertical head loading) and diaphysis (three-point bending test) of the femur of rats administered 0.1% aqueous chokeberry extract (65.74% of polyphenols) or/and Cd in the diet (1 and 5 mg Cd/kg) for 3, 10, 17, and 24 months were evaluated. Moreover, procollagen I was assayed in the bone tissue. The low-level and moderate exposure to Cd decreased procollagen I concentration in the bone tissue and weakened biomechanical properties of the femoral neck and diaphysis. Chokeberry extract administration under the exposure to Cd improved the bone collagen biosynthesis and femur biomechanical properties. The results allow for the conclusion that consumption of chokeberry products under exposure to Cd may improve the bone biomechanical properties and protect from fracture. This study provides support for Aronia melanocarpa berries being a promising natural agent for the skeleton protection under low-level and moderate chronic exposure to Cd.

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