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Representative μCT images of (A) trabecular bone microarchitecture and (B) cortical thickness in Mature and Middle-Aged CON, 5dPTH, and 10dPTH mice. The black boxes overlaying the secondary spongiosa (Fig. 1A) and cortical midshaft (Fig. 1B) represent the regions of analyses and correspond with the representative images provided for each group. There were no significant differences.
Source publication
Intermittent parathyroid hormone (PTH) administration augments bone and progressive bone marrow blood vessel (BMBV) ossification occurs with advancing age. Since intermittent PTH administration augments bone, it may also serve to increase BMBV ossification. We assessed the influence of 5- and 10-days of intermittent PTH 1–34 administration on trabe...
Contexts in source publication
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... 5dPTH The black boxes overlaying the secondary spongiosa (Fig. 1A) and cortical midshaft (Fig. 1B) represent the regions of analyses and correspond with the representative images provided for each group. There were no significant ...
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... 5dPTH The black boxes overlaying the secondary spongiosa (Fig. 1A) and cortical midshaft (Fig. 1B) represent the regions of analyses and correspond with the representative images provided for each group. There were no significant ...
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... no gender-related differences were observed ( Supplementary Tables 1-4), female and male data were pooled and analyzed according to group. Body mass did not differ among groups (Mature CON, 31 ± 2 g; Mature 5dPTH, 32 ± 2 g; Mature 10dPTH, 30 ± 1 g; Middle-Aged CON, 30 ± 1 g; Middle-Aged 5dPTH, 31 ± 1 g; and Middle-Aged 10dPTH, 31 ± 1 g). ...
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... any significant interactions observed for the trabecular bone parameters. As antici- pated, trabecular bone microarchitecture (i.e., BV/TV, Tb.N, Tb.Th, Tb.Sp) did not differ with PTH treatment (Table 1). Likewise, no main effects for age or treatment nor any significant interactions were ob- served for Ct.Th at the femoral mid-shaft (Table 1). Fig. 1 illustrates representative 3D μCT reconstructions of trabecular bone micro- architecture in the secondary spongiosa of the distal femoral meta- physis and Ct.Th. The μCT images of the entire femora are provided to illustrate the regions of analyzes for the trabecular and cortical bone parameters. The black boxes overlaying the ...
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... illustrates representative 3D μCT reconstructions of trabecular bone micro- architecture in the secondary spongiosa of the distal femoral meta- physis and Ct.Th. The μCT images of the entire femora are provided to illustrate the regions of analyzes for the trabecular and cortical bone parameters. The black boxes overlaying the secondary spongiosa (Fig. 1A) and cortical midshaft (Fig. 1B) depict the regions of analyses and correspond to the representative μCT images for each group. In regards to CSMI, significant main effects for age and treatment were observed ( Fig. 2A and 2B, respectively), whereby CSMI was 22% higher (p < 0.05) in Middle-Aged vs. Mature and was lower (p < 0.05) in ...
Context 6
... reconstructions of trabecular bone micro- architecture in the secondary spongiosa of the distal femoral meta- physis and Ct.Th. The μCT images of the entire femora are provided to illustrate the regions of analyzes for the trabecular and cortical bone parameters. The black boxes overlaying the secondary spongiosa (Fig. 1A) and cortical midshaft (Fig. 1B) depict the regions of analyses and correspond to the representative μCT images for each group. In regards to CSMI, significant main effects for age and treatment were observed ( Fig. 2A and 2B, respectively), whereby CSMI was 22% higher (p < 0.05) in Middle-Aged vs. Mature and was lower (p < 0.05) in 5dPTH vs. CON and ...
Similar publications
Osteoporosis is a continuous process of loss of bone tissue. Compared to women, osteoporosis in men is associated with greater morbidity and mortality. In this study, we conducted tomographic and biomechanical evaluations of trabecular and cortical bone in the early stage of male osteoporosis. Male Wistar rats were subjected to orchiectomy and sham...
Citations
... [2] Osteoporosis causes chronic pain and reduced quality of life when it is in more severe expressions, [3] leading to increased healthcare-related funds and an important health issue [4] and increased mortality. [5,6] Even though the presence of known unfavorable clinical and experimental findings, [7][8][9] treatment options for osteoporosis in the elderly are available, such as a well-known bone anabolic agent treatment for osteoporosis, intermittent parathyroid hormone (iPTH), [10] and osteoclast activity inhibitor, denosumab. [9] Despite the fact that pharmaceutical methods are beneficial, non-pharmacochemical approaches, including nutrition and exercise, have been highlighted to prevent ageassociated bone loss and osteoporosis. ...
... Trabecular bone microarchitecture parameters in the distal femoral metaphysis were determined as previously described. [8] Briefly, 60 slices were made in the distal femoral metaphysis, beginning 600 µm superior from the growth plate. Trabecular bone microarchitectural parameters including BV/tissue volume ratio (BV/TV, %), trabecular thickness (Tb.Th, µm), trabecular number (Tb.N, /mm 2 ) and trabecular separation (Tb.Sp, µm) were calculated. ...
... [23,24] Moreover, preclinical evidence suggests that aging is associated with a 57% reduction in osteoblast activity and a 40% reduction in bone mineralization, thereby leading to lower bone cell turnover, resulting in ~53% lower BV in the distal femoral trabecular bone microarchitecture. [25] Although the pharmacological treatment options could lead to some side effects, [7,8,26] the development and use of a number of pharmacological therapies have led to the main treatment options to treat multifactorial processes of osteoporosis progression. For example, iPTH administration is a common therapy for treating osteoporosis. ...
Background:
Aging leads to significant bone loss and elevated osteoporosis risk. Exercise slows age-related bone loss; however, the effects of various moderate-intensity exercise training volumes on bone metabolism remain unclear. This study aimed to determine the degree to which different volumes of moderate-intensity aerobic exercise training influence bone mineral density (BMD), bone mineral content (BMC), femoral trabecular bone microarchitecture, and cortical bone in middle-aged mice.
Methods:
Twenty middle-aged male C57BL/6 mice were randomly assigned 8 weeks of either (1) non-exercise (CON); (2) moderate-intensity with high-volume exercise (EX_MHV); or (3) moderate-intensity with low-volume exercise (EX_MLV) (N=6-7, respectively). Femoral BMD and BMC were evaluated using dual energy X-ray absorptiometry, and trabecular and cortical bone were measured using micro-computed tomography.
Results:
Femoral BMD in EX_MHV but not EX_MLV was significantly higher (P<0.05) than in CON. The distal femoral fractional trabecular bone volume/tissue volume (BV/TV, %) was significantly higher (P<0.05) in both EX_MHV and EX_MLV than in CON mice. Increased BV/TV was induced by significantly increased trabecular thickness (mm) and tended to be higher (P<0.10) in BV (mm3) and lower in trabecular separation (mm) in EX_MHV and EX_MLV than in CON. The femoral mid-diaphysis cortical bone was stronger in EX_MLV than EX_MHV.
Conclusions:
Long-term moderate-intensity aerobic exercise with low to high volumes can be thought to have a positive effect on hindlimb BMD and attenuate age-associated trabecular bone loss in the femur. Moderate-intensity aerobic exercise may be an effective and applicable exercise regimen to prevent age-related loss of BMD and BV.
... Interestingly, Lee and Prisby found that treating mice with daily injections of PTH(1-34), an intermittent regimen, causes coalescence of mineral deposits in femoral bone marrow blood vessels. 25 Similarly, we recently reported that intermittent PTH(1-34) regimen altered the microarchitecture of aortic calcification by promoting the coalescence of calcium deposits. 17 The present study has limitations. ...
Background:
Despite the association of physical activity with improved cardiovascular outcomes and the association of high coronary artery calcification (CAC) scores with poor prognosis, elite endurance athletes have increased CAC. Yet, they nevertheless have better cardiovascular survival. We hypothesized that exercise may transform vascular calcium deposits to a more stable morphology.
Methods:
To test this, hyperlipidemic mice (Apoe-/-) with baseline aortic calcification were separated into 2 groups (n = 9/group) with control mice allowed to move ad-lib while the exercise group underwent a progressive treadmill regimen for 9 weeks. All mice underwent blood collections and in vivo 18F-NaF μPET/μCT imaging both at the start and end of the exercise regimen. At euthanasia, aortic root specimens were obtained for histomorphometry.
Results:
Results showed that, while aortic calcification progressed similarly in both groups based on µCT, the fold change in 18F-NaF density was significantly less in the exercise group. Histomorphometric analysis of the aortic root calcium deposits showed that the exercised mice had a lower mineral surface area index than the control group. The exercise regimen also raised serum PTH levels twofold.
Conclusion:
These findings suggest that weeks-long progressive exercise alters the microarchitecture of atherosclerotic calcium deposits by reducing mineral surface growth, potentially favoring plaque stability.
... All of these modifications serve to aid in the regulation of bone cellular activity and promote an environment supportive of bone formation. A note of caution, however, as recent evidence suggests a potential exacerbation of bone marrow blood vessel ossification with intermittent PTH administration [178]. Interestingly, 2 weeks of intermittent PTH administration improved the age-related decrements in aortic function in old rats [179]. ...
]The microcirculation of bone and marrow is vital for bone development, maintenance, and repair. In addition to the well-known function of transporting oxygen, nutrients, systemic hormones, precursor cells, waste, etc., the bone vascular network plays a role in the mechanical induction of bone formation. In addition, arteries and marrow sinusoids are critical components of hematopoietic stem cell niches. This review discusses the various roles of the bone and marrow microcirculation in regard to (1) bone development, remodeling, and fracture repair; (2) the regulation of bone intramedullary pressure and interstitial fluid flow; and (3) the mobilization of mature blood cells into the peripheral circulation. Age-associated dysfunction of the microcirculation is discussed in relation to how it may disturb bone and marrow homeostasis, fracture repair, and organismal vitality. Finally, the review invites the reader to consider the efficacy of treatments designed to alleviate bone and marrow pathologies in the face of a compromised vascular network.
Advancing age is associated with bone loss and an increased risk of osteoporosis. Exercise training improves bone metabolism and peripheral nerve regeneration, and may play a critical role in osteogenesis and increase in skeletal nerve fiber density. In this study, the potential positive role of aerobic exercise training in bone metabolism and skeletal nerve regeneration was comprehensively evaluated in 14-month-old male C57BL/6 mice. The mice were divided into two groups: no exercise (non-exercise group) and 8-weeks of aerobic exercise training (exercise group), with six mice in each group. Dual-energy X-ray absorptiometry and micro-computed tomography showed that femoral and tibial bone parameters improved after aerobic exercise training. Greater skeletal nerve fiber density was also observed in the distal femoral and proximal tibial periostea, measured and analyzed by immunofluorescence staining and confocal microscopy. Pearson correlation analysis revealed a significant association between skeletal nerve densities and trabecular bone volume/total volume ratios (distal femur; R² = 0.82, p < 0.05, proximal tibia; R² = 0.59, p = 0.07) in the exercise group; while in the non-exercise group no significant correlation was found (distal femur; R² = 0.10, p = 0.54, proximal tibia; R² = 0.12, p = 0.51). Analysis of archival microarray database confirmed that aerobic exercise training changed the microRNA profiles in the mice femora. The differentially expressed microRNAs reinforce the role of aerobic exercise training in the osteogenic and neurogenic potential of femora and tibiae. In conclusion, 8-weeks of aerobic exercise training positively regulate bone metabolism, an effect that paralleled a significant increase in skeletal nerve fiber density. These findings suggest that aerobic exercise training may have dual utility, both as a direct stimulator of bone remodeling and a positive regulator of skeletal nerve regeneration.
The skeleton is highly vascularized due to the various roles blood vessels play in the homeostasis of bone and marrow. For example, blood vessels provide nutrients, remove metabolic by-products, deliver systemic hormones, and circulate precursor cells to bone and marrow. In addition to these roles, bone blood vessels participate in a variety of other functions. This article provides an overview of the afferent, exchange and efferent vessels in bone and marrow and presents the morphological layout of these blood vessels regarding blood flow dynamics. In addition, this article discusses how bone blood vessels participate in bone development, maintenance, and repair. Further, mechanical loading-induced bone adaptation is presented regarding interstitial fluid flow and pressure, as regulated by the vascular system. The role of the sympathetic nervous system is discussed in relation to blood vessels and bone. Finally, vascular participation in bone accrual with intermittent parathyroid hormone administration, a medication prescribed to combat age-related bone loss, is described and age- and disease-related impairments in blood vessels are discussed in relation to bone and marrow dysfunction. © 2020 American Physiological Society. Compr Physiol 10:1009-1046, 2020.
