Bone Resorption (Hardcover, 2005 ed.)

Bone Resorption, the second volume of the series Topics in Bone Biology, is centered on the osteoclast, the bone-resorbing cell. The volume thus c- plements the ?rst volume of the series, Bone Formation, which discussed origin, function, and pathology of the bone-forming cell, the osteoblast.Both volumes are addressed to scientists and clinicians who are active in or wish to enter the ?eld of skeletal function; this group encompasses a wide variety of specialties, including orthopaedics, rheumatology, endocrinology, nephrology, oncology, dentistry, nursing, and chiropractic medicine. Rubin and Green?eld, in the ?rst chapter, discuss the origin and differ- tiation of the osteoclast. Recognized as a multinuclear cell about 150 years ago, its origin was not uncovered until a century later when, as a result of an experiment in which quail and chicken cells were co-cultured, it became clear that osteoclasts arose from hematopoietic stem cells.The authors then discuss the osteoclastogenic factor, now known as RANKL; the inhibitory binding protein, osteoprotegerin (OPG); and the complex signaling pathway that leads to differentiation and late differentiation of this complicated cell. A section of the chapter is devoted to a concise discussion of regulators and repressors of osteoclast differentiation, including sex steroids, calcitonin, nitric oxide, and mechanical factors. The chapter concludes that the ost- clast modulates bone development, bone growth, and