Stroke Prevents Exercise-induced Gains in Bone Microstructure But Not Composition in Mice.
Abstract
Ischemic stroke induces rapid loss in bone mineral density up to 13 times greater
than during normal aging, leading to markedly increased risk of fracture. Little is
known about skeletal changes following stroke beyond density loss. In this study we
use a mild-moderate middle cerebral artery occlusion model to determine the effects
of ischemic stroke without bedrest on bone microstructure, dynamic bone formation,
and tissue composition. Twenty-seven 12-week-old male C57Bl/6J mice received either
a stroke or sham surgery and then either received daily treadmill exercise or remained
sedentary for four weeks. All mice were ambulatory immediately following stroke, and
limb coordination during treadmill exercise was unaffected by stroke, indicating similar
mechanical loading across limbs for surgery groups. Stroke did not directly detriment
microstructure, but exercise only stimulated adaptation in sham group, not stroke
group, with increased bone volume fraction and trabecular thickness in the sham distal
femoral metaphysis. Stroke differentially decreased cortical area in the affected
limb relative to the unaffected limb of the distal femoral metaphysis, and endosteal
bone formation rate in the affected tibial diaphysis. Although exercise failed to
improve bone microstructure following stroke, exercise increased mineral-to-matrix
content in stroke but not sham. Together, these results show that stroke inhibits
exercise-induced changes to femoral microstructure but not tibial composition, even
without changes to gait. Similarly, affected-unaffected limb differences in cortical
bone structure and bone formation rate in ambulatory mice show that stroke affects
bone health even without bedrest.
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https://hdl.handle.net/10161/23243Published Version (Please cite this version)
10.1115/1.4045113Publication Info
Hanne, Nicholas J; Steward, Andrew J; Sessions, Marci R; Thornburg, Hannah L; Sheng,
Huaxin; & Cole, Jacqueline H (2019). Stroke Prevents Exercise-induced Gains in Bone Microstructure But Not Composition
in Mice. Journal of biomechanical engineering, 141(12). 10.1115/1.4045113. Retrieved from https://hdl.handle.net/10161/23243.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Huaxin Sheng
Associate Professor in Anesthesiology
We have successfully developed various rodent models of brain and spinal cord injuries
in our lab, such as focal cerebral ischemia, global cerebral ischemia, head trauma,
subarachnoid hemorrhage, intracerebral hemorrhage, spinal cord ischemia and compression
injury. We also established cardiac arrest and hemorrhagic shock models for studying
multiple organ dysfunction. Our current studies focus on two projects. One is to
examine the efficacy of catalytic antioxidant in treating cerebral is

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