Calcium fluxes within cortical bone fluid may affect osteocyte mechanosensitivity

摘要

Through bone remodelling, bone tissue adapts its structure to its environment, repairs damage and regulates calcium homoeostasis (Kusuzaki et al. 2000; Burr 2002). Indeed, bone acts as a calcium reservoir supplying the body calcium demands and absorbing calcium excess (Heaney 2002). Calcium fluxes appearing in the bone interstitial fluid, not necessarily related to bone remodelling activity, are tightly related to osteocyte's mechano-transduction (Marenzana et al. 2005; Qing and Bonewald 2009). In this communication, we investigate the effects of the calcium concentration on osteocyte's response. In particular, we extend our previous models of chemical and hydraulic transport of monovalent ions in the canalicular network (Lemaire et al. 2008; Kaiser et al. 2009; Lemaire et al. 2010) to describe the calcium transport. Eventually, we discuss the influence of the calcium concentration and flux on the fluid transport and on the shear stress perceived by osteocytes.