[Biochemical markers of bone turnover. New aspect. Nitric oxide synthase and bone metabolism].

It remains to be determined the role of the nitric oxide synthase (NOS) system in bone metabolism. We addressed this point in mice with complete disruption of the NOS system (triply n/i/eNOS(-/-) mice) that we have recently developed, and clarified that the triply NOS( - / - ) mice manifested increased bone mineral density and accelerated bone turnover in vivo. These results provide the first direct evidence that the entire NOS system plays an important role in the regulation of bone metabolism.