title: Natriuretic hormone receptors and actions on bone endothelial cells.
abstract: [125I]Atrial natriuretic peptide (ANP) was used to identify ANP receptors on a clonal line of bovine bone endothelial (BBE) cells. Specific binding of [125I]ANP was saturable and of high affinity. Computer analysis of the equilibrium binding data indicated that the Scatchard plots are best fit by a straight line (Kd = 69.3 +/- 20.9 pM; binding capacity = 37.9 fmol/10(6) cells). The order of potency for competing with [125I]ANP binding was human ANP (hANP) > rat atriopeptin-1 (rAP-1) > porcine brain natriuretic peptide (pBNP) > porcine C-type natriuretic peptide. Affinity cross-linking studies indicated the presence of two major 130- and 70-kilodalton bands that specifically bound to hANP, rAP-1, pBNP, and porcine C-type natriuretic peptide. The binding of natriuretic peptides to BBE cells resulted in an increase in cGMP production and a significant decrease in Na+/K+/Cl- cotransport, without effects on cAMP intracellular accumulation. hANP, rAP-1, and pBNP at 100-nM concentrations, significantly inhibited PTH-induced cAMP production. Treatment with natriuretic hormones was also associated with an increase in 6-keto-prostaglandin F1 alpha levels in the culture medium of BBE cells and a higher cell growth rate. These studies demonstrate that bone endothelial cells bear receptors for natriuretic hormones associated with changes in PTH-induced cAMP production, prostaglandin production, and cell proliferation.
authors.affiliation: Department of Clinical Pathophysiology, University of Florence, Italy.
authors.forename: M L
authors.initials: ML
authors.lastname: De Feo
authors.forename: F
authors.initials: F
authors.lastname: Franceschelli
authors.forename: U
authors.initials: U
authors.lastname: Frediani
authors.forename: C
authors.initials: C
authors.lastname: Tosti-Guerra
authors.forename: C
authors.initials: C
authors.lastname: Crescioli
authors.forename: A
authors.initials: A
authors.lastname: Tanini
authors.forename: O
authors.initials: O
authors.lastname: Bartolini
authors.forename: A
authors.initials: A
authors.lastname: Becorpi
authors.forename: M
authors.initials: M
authors.lastname: Serio
authors.forename: M L
authors.initials: ML
authors.lastname: Brandi
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism*; D002455:Cell Division; D002999:Clone Cells; D003432:Cross-Linking Reagents; D004573:Electrolytes / Q000378:metabolism; D004727:Endothelium / Q000166:cytology / Q000378:metabolism; D006801:Humans; D020097:Natriuretic Peptide, Brain; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009712:Nucleotides, Cyclic / Q000096:biosynthesis; D011453:Prostaglandins / Q000096:biosynthesis; D051381:Rats; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism*; D013552:Swine
chemical_list: D003432:Cross-Linking Reagents; D004573:Electrolytes; D009419:Nerve Tissue Proteins; D009712:Nucleotides, Cyclic; D011453:Prostaglandins; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor