Do More Highly Organized Collagen Fibrils Increase Bone Mechanical Strength in Loss of Mineral Density After One-Year Running Training?

Puustjärvi, Kaija; Nieminen, Jyrki; Räsänen, Tuomas; Hyttinen, Marko; Helminen, Heikki J.; Kröger, Heikki; Huuskonen, J; Alhava, Esko; Kovanen, Vuokko

doi:10.1359/jbmr.1999.14.3.321

Cited by 59 publications

(57 citation statements)

References 62 publications

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“…Previous studies have shown equivocal effects of long distance running on bone mass especially in postmenopausal women [ 1 1,121. In dogs, running caused a significant reduction in bone mineral density [20]. Since both IGF-I and TGFP are potent stimulators of bone formation, we expect that the bone concentrations of these growth factors are in parallel with the bone mass.…”

Section: Discussionmentioning

confidence: 99%

The effect of exercise on systemic and bone concentrations of growth factors in rats

Bravenboer

Engelbregt

Visser

et al. 2001

Journal Orthopaedic Research

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Exercise can prevent bone loss and increase bone density. Growth factors such as insulin-like growth factor-I (IGF-I) and transforming growth factor P (TGFB) are thought to be involved in the local response to mechanical loading, resulting in bone remodelling. We tested the effect of additional weight bearing during exercise on the systemic response of IGF-I and local bone response of IGF-I and TGFP.Thirty-four female Wistar rats (aged 3 months, weight 226.9 4~ 20.2 g) were randomly divided in four groups: group 1 baseline controls; group 2 sedentary controls; group 3 ran 15 min a day on a motor-driven exercise belt: group 4 ran 15 min a day with a backpack containing 40 g. The animals ran 5 days a week, for 6 weeks, with an average velocity of 16.6 i 4.4 mlmin, and a slope of 5" uphill.The serum growth hormone (GH) concentration was significantly higher in the running rats (group 3, P = 0.009) than in the sedentary controls (group 2). The IGF-I and I G F binding protein 3 (IGFBP3) levels in serum and the IGF-I levels in liver were similar in all groups. In the tibia no significant differences were observed in IGF-I, IGFBP3 and TGFP concentration. In the humerus, the IGF-I concentration was lower in the running rats (group 3 ) than in the sedentary controls ( P = 0.04), but it was higher in the rats that ran with additional weight than in those without ( P = 0.009). The TGFP concentration in the humerus was lower in both group 3 ( P = 0,001) and 4 (P = 0.03) than in the sedentary controls.The effects in bone caused by mechanical stimulation cannot be explained by changes in serum IGF-I and IGF-I produced in the liver. The concentrations of IGF-I and TGFP in bone appeared to be modulated by running exercise. 0

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Section: Discussionmentioning

confidence: 99%

The effect of exercise on systemic and bone concentrations of growth factors in rats

Bravenboer

Engelbregt

Visser

et al. 2001

Journal Orthopaedic Research

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“…For example, it has been reported in dogs that a 10% reduction in vertebral BMD elicited by a strenuous progressive running programme (up to 40 km/day) for 1 year did not change the bone mechanical properties. [19] These dogs, compared with their sedentary counterparts, showed reorganization of the collagen fibres in a more parallel manner without changes in the concentration of crosslinks, suggesting that collagen reorganization during exercise may contribute to the maintenance of bone strength despite decreased mineral density. [19] Bone mechanical properties are modified depending on loading, such that bone strength is enhanced or reduced in response to either increased or reduced mechanical loading.…”

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confidence: 84%

“…[19] These dogs, compared with their sedentary counterparts, showed reorganization of the collagen fibres in a more parallel manner without changes in the concentration of crosslinks, suggesting that collagen reorganization during exercise may contribute to the maintenance of bone strength despite decreased mineral density. [19] Bone mechanical properties are modified depending on loading, such that bone strength is enhanced or reduced in response to either increased or reduced mechanical loading. [3,[20][21][22] The adaptive response is very complex and depends on the characteristics of loading history, but also on systemic and local factors, which include neuroendocrine, endocrine and paracrine changes in metabolites, cytokines, growth factors, hormones, vitamins and minerals.…”

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confidence: 84%

Exercise and Bone Mass in Adults

et al. 2009

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“…4,6,7 Most studies focused on bone development and growth in rabbits, investigating the development of the primary and secondary ossification centers or evaluating bone growth at the growth plate. [8][9][10] Other studies showed that BMD increases and biomechanical properties change concurrently during maturation and growth.…”

Section: Introductionmentioning

confidence: 99%

Collagen and mineral deposition in rabbit cortical bone during maturation and growth: Effects on tissue properties

Isaksson

Harjula

Koistinen

et al. 2010

Journal Orthopaedic Research

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ABSTRACT:We characterized the composition and mechanical properties of cortical bone during maturation and growth and in adult life in the rabbit. We hypothesized that the collagen network develops earlier than the mineralized matrix. Growth was monitored, and the rabbits were euthanized at birth (newborn), and at 1, 3, 6, 9, and 18 months of age. The collagen network was assessed biochemically (collagen content, enzymatic and non-enzymatic cross-links) in specimens from the mid-diaphysis of the tibia and femur and biomechanically (tensile testing) from decalcified whole tibia specimens. The mineralized matrix was analyzed using pQCT and 3-point bend tests from intact femur specimens. The collagen content and the Young's modulus of the collagen matrix increased significantly until the rabbits were 3 months old, and thereafter remained stable. The amount of HP and LP collagen cross-links increased continuously from newborn to 18 months of age, whereas PEN cross-links increased after 6 months of age. Bone mineral density and the Young's modulus of the mineralized bone increased until the rabbits were at least 6 months old. We concluded that substantial changes take place during the normal process of development in both the biochemical and biomechanical properties of rabbit cortical bone. In cortical bone, the collagen network reaches its mature composition and mechanical strength prior to the mineralized matrix. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J. Orthop. Res. 28: 1626Res. 28: -1633Res. 28: , 2010 Keywords: maturation; growth; aging; rabbit; bone; mechanical properties; composition Collagen is the principal structural component of bone matrix, accounting for about 1/3 of mineralized bone tissues. 1 During development, bone formation and growth rates are regulated by genetic and hormonal factors, and by external factors such as mechanical loading that interact to determine the final anatomy and strength of the skeleton. 1-3 During this period, bone also changes in its composition, structure, and function. The organic matrix changes its composition and structural organization, and mechanical stiffness increases with increased bone mineral density (BMD). 3,4 The majority (>80%) of the mineral can be found within the collagen fibril network, 5 but limited information is available about the factors that determine the normal deposition of mineral, for example, the timing and how this can determine the properties of the adult tissue.The structure and function of maturing and growing bone were studied in several animal models. 4,6,7 Most studies focused on bone development and growth in rabbits, investigating the development of the primary and secondary ossification centers or evaluating bone growth at the growth plate. [8][9][10] Other studies showed that BMD increases and biomechanical properties change concurrently during maturation and growth. 4,6 However, the development of the collagen framework has been less extensively studied. During development, at least in the equine, ...

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Do More Highly Organized Collagen Fibrils Increase Bone Mechanical Strength in Loss of Mineral Density After One-Year Running Training?

Abstract: The aim of this study was to evaluate the effects of long-term running training on the structural properties of bone.

Cited by 59 publications

References 62 publications

The effect of exercise on systemic and bone concentrations of growth factors in rats

The effect of exercise on systemic and bone concentrations of growth factors in rats

Exercise and Bone Mass in Adults

Collagen and mineral deposition in rabbit cortical bone during maturation and growth: Effects on tissue properties

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