Loading-related reorientation of bone proteoglycan in vivo. Strain memory in bone tissue?
The load-carrying capacity of the skeleton is achieved and maintained as the result of a continued functional stimulus to the cell populations responsible for bone remodeling. Although some bone cells have been assumed to be influenced by the load-induced changes in strain throughout the matrix, no evidence is available to indicate which cells are susceptible to such strain change or how such transient events provide a sustained influence on cell behaviour. In the present study, we showed that a short period of dynamic loading in vivo affects the orientation of proteoglycan within bone tissue. This reorientation declines only slowly, thus providing a persistent record of the tissue's recent strain history. Such a record has the ability not only to "capture" strain transients but also to "update" and "average" them. In this way, the bone cells could be presented with a sustained and coherent stimulus directly related to dynamic strain transients. These transients are the tissue's principal function variable.
Skerry
T M
TM
Department of Anatomy, Royal Veterinary College, London, England.
Bitensky
L
L
Chayen
J
J
Lanyon
L E
LE
D000222:Adaptation, Physiological; D000423:Alcian Blue; D000818:Animals; D001696:Biomechanical Phenomena; D001718:Birefringence; D001842:Bone and Bones / Q000502:physiology*; D010012:Osteogenesis; D011509:Proteoglycans / Q000502:physiology*; D013314:Stress, Mechanical; D014422:Turkeys
D011509:Proteoglycans; D000423:Alcian Blue