Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation.

Bone formation is not impaired by hibernation (disuse) in black bears Ursus americanus.

Disuse by bed rest, limb immobilization or space flight causes rapid bone loss by arresting bone formation and accelerating bone resorption. This net bone loss increases the risk of fracture upon remobilization. Bone loss also occurs in hibernating ground squirrels, golden hamsters, and little brown bats by arresting bone formation and accelerating bone resorption. There is some histological ev...

Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hi...

Exploration of the role of serum factors in maintaining bone mass during hibernation in black bears

Bending Properties, Porosity, and Ash Fraction of Cortical Bone from Black Bear (ursusamericanus) Tibias Are Not Compromised with Aging despite Annual Periods of Disuse

Introduction Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, which leads to bone fragility and increased fracture risk. For prolonged bed rest, immobilization, and space flight, disuse atrophy of bone is prevalent in many animals including humans. However, black bears may not develop osteopenia during long periods of disuse (i.e., hibernatio...

Serum Immune-Related Proteins are Differentially Expressed during Hibernation in the American Black Bear

Hibernation is an adaptation to conserve energy in the face of extreme environmental conditions and low food availability that has risen in several animal phyla. This phenomenon is characterized by reduced metabolic rate (∼25% of the active basal metabolic rate in hibernating bears) and energy demand, while other physiological adjustments are far from clear. The profiling of the serum proteome ...