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A low protein diet alters bone material level properties and the response to in vitro repeated mechanical loading.

Dubois-Ferrière V, Rizzoli R, Ammann P - Biomed Res Int (2014)

Bottom Line: However, it remains unknown whether these alterations of bone tissue could influence the response to repeated mechanical loading.Humeri were then monotonically loaded to failure.Material level properties were also evaluated through a nanoindentation test.

View Article: PubMed Central - PubMed

Affiliation: Division of Bone Diseases, Department of Internal Medicine Specialties, University of Geneva Hospitals and Faculty of Medicine, 4 Rue Gabrielle Perret-Gentil, 1211 Geneva 14, Switzerland.

ABSTRACT
Low protein intake is associated with an alteration of bone microstructure and material level properties. However, it remains unknown whether these alterations of bone tissue could influence the response to repeated mechanical loading. The authors investigated the in vitro effect of repeated loading on bone strength in humeri collected from 20 6-month-old female rats pair-fed with a control (15% casein) or an isocaloric low protein (2.5% casein) diet for 10 weeks. Bone specimens were cyclically loaded in three-point bending under load control for 2000 cycles. Humeri were then monotonically loaded to failure. The load-displacement curve of the in vitro cyclically loaded humerus was compared to the contralateral noncyclically loaded humerus and the influence of both protein diets. Material level properties were also evaluated through a nanoindentation test. Cyclic loading decreased postyield load and plastic deflection in rats fed a low protein diet, but not in those on a regular diet. Bone material level properties were altered in rats fed a low protein diet. This suggests that bone biomechanical alterations consequent to cyclic loading are more likely to occur in rats fed a low protein diet than in control animals subjected to the same in vitro cyclic loading regimen.

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Related in: MedlinePlus

Postyield load and deflection in monotonically loaded humerus of 6-month-old rats fed either normal casein (15%) or low casein diet (2.5%). Humeri were either previously cyclically loaded (open columns) or served as control (dark columns). Values are means ± SEM. *P < 0.05 versus 2.5% casein diet.
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fig3: Postyield load and deflection in monotonically loaded humerus of 6-month-old rats fed either normal casein (15%) or low casein diet (2.5%). Humeri were either previously cyclically loaded (open columns) or served as control (dark columns). Values are means ± SEM. *P < 0.05 versus 2.5% casein diet.

Mentions: In rats fed a low protein diet, maximal load and stiffness showed a trend to a decrease but it was not statistically significant after cyclic loading (Table 2). However, postyield load and plastic deflection were both significantly decreased (−45% and −30%, resp.) after loading, resulting in a significant decrease of plastic energy (−38%) (Figure 3).


A low protein diet alters bone material level properties and the response to in vitro repeated mechanical loading.

Dubois-Ferrière V, Rizzoli R, Ammann P - Biomed Res Int (2014)

Postyield load and deflection in monotonically loaded humerus of 6-month-old rats fed either normal casein (15%) or low casein diet (2.5%). Humeri were either previously cyclically loaded (open columns) or served as control (dark columns). Values are means ± SEM. *P < 0.05 versus 2.5% casein diet.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150450&req=5

fig3: Postyield load and deflection in monotonically loaded humerus of 6-month-old rats fed either normal casein (15%) or low casein diet (2.5%). Humeri were either previously cyclically loaded (open columns) or served as control (dark columns). Values are means ± SEM. *P < 0.05 versus 2.5% casein diet.
Mentions: In rats fed a low protein diet, maximal load and stiffness showed a trend to a decrease but it was not statistically significant after cyclic loading (Table 2). However, postyield load and plastic deflection were both significantly decreased (−45% and −30%, resp.) after loading, resulting in a significant decrease of plastic energy (−38%) (Figure 3).

Bottom Line: However, it remains unknown whether these alterations of bone tissue could influence the response to repeated mechanical loading.Humeri were then monotonically loaded to failure.Material level properties were also evaluated through a nanoindentation test.

View Article: PubMed Central - PubMed

Affiliation: Division of Bone Diseases, Department of Internal Medicine Specialties, University of Geneva Hospitals and Faculty of Medicine, 4 Rue Gabrielle Perret-Gentil, 1211 Geneva 14, Switzerland.

ABSTRACT
Low protein intake is associated with an alteration of bone microstructure and material level properties. However, it remains unknown whether these alterations of bone tissue could influence the response to repeated mechanical loading. The authors investigated the in vitro effect of repeated loading on bone strength in humeri collected from 20 6-month-old female rats pair-fed with a control (15% casein) or an isocaloric low protein (2.5% casein) diet for 10 weeks. Bone specimens were cyclically loaded in three-point bending under load control for 2000 cycles. Humeri were then monotonically loaded to failure. The load-displacement curve of the in vitro cyclically loaded humerus was compared to the contralateral noncyclically loaded humerus and the influence of both protein diets. Material level properties were also evaluated through a nanoindentation test. Cyclic loading decreased postyield load and plastic deflection in rats fed a low protein diet, but not in those on a regular diet. Bone material level properties were altered in rats fed a low protein diet. This suggests that bone biomechanical alterations consequent to cyclic loading are more likely to occur in rats fed a low protein diet than in control animals subjected to the same in vitro cyclic loading regimen.

Show MeSH
Related in: MedlinePlus