A neuro (endo)crine regulation of bone remodeling

Bone remodeling is the normal physiologic process that is used by vertebrates to maintain a constant bone mass during the period bracketed by the end of puberty and the onset of gonadal failure in later life. Besides the well-characterized and critical process of local regulation of bone remodeling, achieved by autocrine and paracrine mechanisms, recent genetic studies have shown that there is a central control of bone formation, mediated by a neuroendocrine mechanism. This central regulation involves leptin, an adipocyte-secreted hormone that controls body weight, reproduction and bone remodeling, and which binds to and exerts its effect through the cells of the hypothalamic nuclei in the brain. This genetic result in mice is in line with clinical observations in humans and generates a whole new direction of research in bone physiology. BioEssays 22:970-975, 2000.