title: The noncalcemic analogue of vitamin D, 22-oxacalcitriol, suppresses parathyroid hormone synthesis and secretion.
abstract: OCT, a non-calcemic analogue of 1,25(OH)2D3 has been found to have a more potent activity than that of 1,25(OH)2D3 regarding cell differentiation and immunopotentiation activity, and to prolong the average life span of MRL/l mice. Recently, we found that OCT effectively suppressed the secretion and synthesis of PTH without inducing hypercalcemia. In primary cultures of bovine parathyroid cells, OCT was capable of suppressing PTH release in a dose-dependent manner. OCT was also active in vivo, and, like 1,25(OH)2D3, decreased the pre-pro(PTH) mRNA levels. In a group of rats with CRF, daily administration of OCT, 8 ng i.p. for 2 weeks returned PTH levels to normal without changes in serum calcium. Preliminary results in dogs with CRF indicated that after the administration of OCT 5 micrograms i.v., N-terminal PTH decreased by 76% without changes in Ca. In conclusion, OCT may provide a unique contribution to the treatment of secondary hyperparathyroidism.
authors.affiliation: Research Laboratory of Chugai Pharmaceutical Co., Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nishii
authors.forename: J
authors.initials: J
authors.lastname: Abe
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.forename: A J
authors.initials: AJ
authors.lastname: Brown
authors.forename: A S
authors.initials: AS
authors.lastname: Dusso
authors.forename: J
authors.initials: J
authors.lastname: Finch
authors.forename: S
authors.initials: S
authors.lastname: Lopez-Hilker
authors.forename: J
authors.initials: J
authors.lastname: Morrissey
authors.forename: E
authors.initials: E
authors.lastname: Slatopolsky
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D002478:Cells, Cultured; D006801:Humans; D010281:Parathyroid Hormone / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D010281:Parathyroid Hormone; D002117:Calcitriol; C051883:maxacalcitol