PARATHYROID HORMONE-RELATED PROTEIN-(1-37) INDUCES CAMP RESPONSE IN HUMAN OSTEOBLAST-LIKE CELLS

During recent years parathyroid hormone-related protein (PTHrP) resear ch has been focused on the physiological functions of different fragme nts of the PTHrP molecule. Here we demonstrate that PTHrP (1-37) induc ed cyclic adenosine monophosphate (cAMP) response in primary human ost eoblast-like cells, which were well characterized by the presence of a lkaline phosphatase activity and osteocalcin production after stimulat ion with 1,25-dihydroxyvitamin D-3. However, there was no cAMP respons e to PTHrP (58-77). Furthermore, the response to PTHrP (1-37) was dose dependent, with a significant increase at 1 nM. The presence of PTHrP (1-37)-induced cAMP response in human osteoblast-like cells implies t hat aminoterminal PTHrP fragments may exert important functions in the bone.