title: [Musculoskeletal rehabilitation and bone. Mechanical stress and bone quality : do mechanical stimuli alter collagen cross-link formation in bone? "Yes" ].
abstract: Evidence has accumulated that collagen cross-links also play important roles in bone strength and the proper biological functions of bone. Thus, collagen cross-links may be a factor in determining the material properties of bone. Collagen cross-linking is affected by some growth factors, and tissue age. Collagen cross-links can be roughly divided into two types : lysyl oxidase mediated cross-links (enzymatic immature, divalent and mature, trivalent cross-links) and advanced glycation end-products (AGE ; non-enzymatic, pentosidine cross-links). These two types vary by both the mechanism of formation and by functional differences. Hyper- and micro-gravity, weight-bearing, and low intensity pulsed ultrasound (LIPUS) have distinct biological effects on bone collagen cross-link formation in vitro and in vivo (Saito M, J Bone Miner Res 2003, Bone 2004, Calcif Tissue Int 2004) . We demonstrated in previous studies that physiologic levels of mechanical strain such as hypergravity, weight-bearing, and LIPUS induce the formation of bone-type collagenous matrix into a specific molecular packing arrangement through the formation of characteristic types of cross-links as mineralization begins. Collagen cross-links play important roles in the expression of bone strength and the proper biological function of bone. Thus, collagen cross-links are thought to be a determinant of bone quality. While LIPUS have beneficial effects on collagen enzymatic cross-link formation, mechanical stress may improve bone quality (Saito M, Osteoporos Int, REVIEW, 2010) .
authors.affiliation: Department of Orthopaedic Surgery, The Jikei University School of Medicine.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Saito
authors.forename: Keishi
authors.initials: K
authors.lastname: Marumo
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism*; D002113:Calcification, Physiologic; D003094:Collagen / Q000378:metabolism*; D017102:Fracture Healing / Q000502:physiology; D050723:Fractures, Bone / Q000517:prevention & control; D017127:Glycation End Products, Advanced; D006801:Humans; D018471:Hypergravity; D010006:Osteoblasts / Q000502:physiology; D013314:Stress, Mechanical; D014465:Ultrasonics; D016474:Weight-Bearing / Q000502:physiology
chemical_list: D017127:Glycation End Products, Advanced; D003094:Collagen