Parathyroid hormone (PTH) will be available in a few months for the treatment of osteoporosis. When used as a single daily subcutaneous injection for at least 1 year, it increases bone mass and reduces fracture rate more efficiently than the usual anti-resorptive therapy. Recently published articles show that PTH can act through different intracellular signaling pathways, depending on its concentration, time of exposure and molecular fragments. High concentration and prolonged exposure to amino-terminal PTH fragments stimulate bone resorption. On the other hand, in an intermittent way and in low concentrations, PTH administration increases bone formation. This review aims to present the principal results of clinical and experimental researches on PTH actions, while trying to explain the rationale for its dual effect on bone remodeling.
Parathyroid hormone; PTH; Osteoporosis; Treatment
