Biologic effects of parathyroid hormone metabolites: implications for renal bone disease.

PTH fragments consisting of the C-terminal portion of the molecule may have biologic effects and may modify the actions of PTH. Evidence for the presence of a C-terminal PTH receptor further supports a biologic role for such fragments. Because C-PTH fragments accumulate in patients with renal insufficiency, it is possible that they may contribute to renal bone disease. The precise role of circulating C-PTH fragments in the pathogenesis, diagnosis, and management of renal osteodystrophy, however, remains to be determined. Future studies of the biologic effects and regulation of these fragments may lead to better understanding of skeletal biology and may also improve our approach to the diagnosis and treatment of renal bone disease.