title: Carboxyl-terminal parathyroid hormone fragments: biologic effects.
abstract: Carboxyl-terminal PTH fragments (C-PTH), are generated by both direct secretion from parathyroids in relation to serum calcium levels and catabolism of PTH operated by the Kupffer cells in the liver. These molecular fragments have been till recently regarded as inert byproducts of PTH metabolism, since they do not interact with the PTH/PTH-related peptide (rP) receptor, which mediates the classical hormone actions. Current findings instead indicate that C-PTH would interact with a putative C-PTH receptor. This way, C-PTH seem to exert specific effects on calcium homeostasis and bone metabolism, opposite to those of the synthetic agonist of PTH/PTHrP receptor (i.e. PTH 1-34). In vitro and in vivo data actually indicate that C-PTH, by interacting with specific receptors, could have an anti-calcemic action, as well as a pro-apoptotic effect on both osteocytes and osteoclasts. This in turn could result in a reduced activity of the latter cells, with a consequent inhibition of bone resorption.
authors: Ospedale Casa Sollievo della Sofferenza, IRCCS, San Giovanni Rotondo, Foggia, Italy. alscill@tin.it
authors: A
authors: A
authors: Scillitani
authors: V
authors: V
authors: Guarnieri
authors: C
authors: C
authors: Battista
authors: I
authors: I
authors: Chiodini
authors: A S
authors: AS
authors: Salcuni
authors: S
authors: S
authors: Minisola
authors: C M
authors: CM
authors: Francucci
authors: V
authors: V
authors: Carnevale
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001862:Bone Resorption / Q000188:drug therapy; D002117:Calcitriol / Q000502:physiology; D002118:Calcium / Q000097:blood / Q000378:metabolism; D006801:Humans; D006934:Hypercalcemia / Q000188:drug therapy; D010010:Osteoclasts / Q000187:drug effects; D010011:Osteocytes / Q000187:drug effects; D010281:Parathyroid Hormone / Q000037:antagonists & inhibitors / Q000097:blood / Q000502:physiology*; D010446:Peptide Fragments / Q000097:blood / Q000502:physiology*; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000378:metabolism; D018016:Receptors, Parathyroid Hormone / Q000378:metabolism
chemical_list: D010281:Parathyroid Hormone; D010446:Peptide Fragments; D044168:Receptor, Parathyroid Hormone, Type 1; D018016:Receptors, Parathyroid Hormone; C023443:carboxyl-terminal parathyroid hormone; D002117:Calcitriol; D002118:Calcium