Protective Effects of Controlled Mechanical Loading of Bone in C57BL6/J Mice Subject to Disuse

• DOI: 10.1002/jbm4.10322
• Publication Date: 2019-12-03T03:54:24Z
• Authors: Alex DeLong; Michael A Friedman; Scott M Tucker; Andrew R Krause; Allen Kunselman; Henry J Donahue; Gregory S Lewis
• Keywords: Hindlimb; Spaceflight; Weight-bearing; Biomechanics

Prolonged reduction in weightbearing causes bone loss. Disuse of is associated with recovery from common musculoskeletal injury and trauma, bed rest resulting various medical conditions, spaceflight. The hindlimb-suspension rodent model popular for simulating unloading disuse. We hypothesized that controlled mechanical loading the tibia would protect against loss occurring concurrent Additionally, we areas high peak strains (midshaft) provide more protection than lower strain (distal shaft). Adult C57BL6/J mice were suspended 3 weeks, one limb subjected to tibial compression four times per week. μCT imaging was completed at days 0, 11, 21, addition serum analysis. Significant caused by hindlimb suspension detected trabecular day 11 worsened 21 (p < 0.05). Bone also cortical thickness area fraction 21. However, short bouts week compressive protected loaded much this At observed a 50% volume/total volume 6% midshaft unloaded limbs, but only 15% 2% corresponding losses contralateral limbs = 0.001 p 0.02). Many geometry parameters animals did not significantly differ non-suspended control limbs. Conversely, protective effect lower-strained distal shaft. Analysis metabolism markers suggested benefits occurred through increased formation instead decreased resorption. This study uniquely isolates role externally applied mouse tibia, absence muscle stimulation, protecting disuse-related loss, demonstrates limited may be highly effective during prolonged © 2019 Authors. JBMR Plus published Wiley Periodicals, Inc. on behalf American Society Mineral Research.