Tibial loading increases osteogenic gene expression and cortical bone volume in mature and middle-aged mice.

ABSTRACT: There are conflicting data on whether age reduces the response of the skeleton to mechanical stimuli. We examined this question in female BALB/c mice of different ages, ranging from young to middle-aged (2, 4, 7, 12 months). We first assessed markers of bone turnover in control (non-loaded) mice. Serum osteocalcin and CTX declined significantly from 2 to 4 months (p<0.001). There were similar age-related declines in tibial mRNA expression of osteoblast- and osteoclast-related genes, most notably in late osteoblast/matrix genes. For example, Col1a1 expression declined 90% from 2 to 7 months (p<0.001). We then assessed tibial responses to mechanical loading using age-specific forces to produce similar peak strains (-1300 µε endocortical; -2350 µε periosteal). Axial tibial compression was app

SUBMITTER: Silva MJ 

PROVIDER: S-EPMC3325918 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature