TY - JOUR
T1 - Bone Plasticity in Response to Exercise Is Sex-Dependent in Rats
AU - Vicente, Wagner S.
AU - dos Reis, Luciene M.
AU - Graciolli, Rafael G.
AU - Graciolli, Fabiana G.
AU - Dominguez, Wagner V.
AU - Wang, Charles C.
AU - Fonseca, Tatiana L.
AU - Velosa, Ana P.
AU - Roschel, Hamilton
AU - Teodoro, Walcy R.
AU - Gualano, Bruno
AU - Jorgetti, Vanda
PY - 2013/5/31
Y1 - 2013/5/31
N2 - Purpose:To characterize the potential sexual dimorphism of bone in response to exercise.Methods:Young male and female Wistar rats were either submitted to 12 weeks of exercise or remained sedentary. The training load was adjusted at the mid-trial (week 6) by the maximal speed test. A mechanical test was performed to measure the maximal force, resilience, stiffness, and fracture load. The bone structure, formation, and resorption were obtained by histomorphometric analyses. Type I collagen (COL I) mRNA expression and tartrate-resistant acid phosphatase (TRAP) mRNA expression were evaluated by quantitative real-time PCR (qPCR).Results:The male and female trained rats significantly improved their maximum speed during the maximal exercise test (main effect of training; p<0.0001). The male rats were significantly heavier than the females, irrespective of training (main effect of sex; p<0.0001). Similarly, both the weight and length of the femur were greater for the male rats when compared with the females (main effect of sex; p<0.0001 and p<0.0001, respectively). The trabecular volume was positively affected by exercise in male and female rats (main effect of training; p = 0.001), whereas the trabecular thickness, resilience, mineral apposition rate, and bone formation rate increased only in the trained males (within-sex comparison; p<0.05 for all parameters), demonstrating the sexual dimorphism in response to exercise. Accordingly, the number of osteocytes increased significantly only in the trained males (within-sex comparison; p<0.05). Pearson's correlation analyses revealed that the COL I mRNA expression and TRAP mRNA expression were positively and negatively, respectively, related to the parameters of bone remodeling obtained from the histomorphometric analysis (r = 0.59 to 0.85; p<0.05).Conclusion:Exercise yielded differential adaptations with respect to bone structure, biomechanical proprieties, and molecular signaling in male and female rats.
AB - Purpose:To characterize the potential sexual dimorphism of bone in response to exercise.Methods:Young male and female Wistar rats were either submitted to 12 weeks of exercise or remained sedentary. The training load was adjusted at the mid-trial (week 6) by the maximal speed test. A mechanical test was performed to measure the maximal force, resilience, stiffness, and fracture load. The bone structure, formation, and resorption were obtained by histomorphometric analyses. Type I collagen (COL I) mRNA expression and tartrate-resistant acid phosphatase (TRAP) mRNA expression were evaluated by quantitative real-time PCR (qPCR).Results:The male and female trained rats significantly improved their maximum speed during the maximal exercise test (main effect of training; p<0.0001). The male rats were significantly heavier than the females, irrespective of training (main effect of sex; p<0.0001). Similarly, both the weight and length of the femur were greater for the male rats when compared with the females (main effect of sex; p<0.0001 and p<0.0001, respectively). The trabecular volume was positively affected by exercise in male and female rats (main effect of training; p = 0.001), whereas the trabecular thickness, resilience, mineral apposition rate, and bone formation rate increased only in the trained males (within-sex comparison; p<0.05 for all parameters), demonstrating the sexual dimorphism in response to exercise. Accordingly, the number of osteocytes increased significantly only in the trained males (within-sex comparison; p<0.05). Pearson's correlation analyses revealed that the COL I mRNA expression and TRAP mRNA expression were positively and negatively, respectively, related to the parameters of bone remodeling obtained from the histomorphometric analysis (r = 0.59 to 0.85; p<0.05).Conclusion:Exercise yielded differential adaptations with respect to bone structure, biomechanical proprieties, and molecular signaling in male and female rats.
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U2 - 10.1371/journal.pone.0064725
DO - 10.1371/journal.pone.0064725
M3 - Article
C2 - 23741378
AN - SCOPUS:84878525457
SN - 1932-6203
VL - 8
JO - PloS one
JF - PloS one
IS - 5
M1 - e64725
ER -