title: Mechanism in inhibitory effects of vitamin K2 on osteoclastic bone resorption: in vivo study in osteopetrotic (op/op) mice.
abstract: Osteoclast deficiency in op/op mice was cured by a single injection of 5 micrograms recombinant human macrophage colony-stimulating factor (M-CSF). On d 5, the osteoclast number reached a maximum value. By d 15, the osteoclast number had decreased to about 70% of the maximum level. Moreover, by d 20, the osteoclast number had decreased to about 30% of its maximum level. On d 5, the osteoclast number of vitamin K2 12 h previously had decreased to about 30% of the M-CSF-only injected mice. Moreover, on d 5, the osteoclast number of the mice receiving a single injection of vitamin K2 24 h previously had decreased to about 15% that of mice injected only with M-CSF. These results indicate that vitamin K2 inhibits in vivo osteoclast formation. On d 20, the osteoclast number of the mice injected with a single dose of vitamin K2 12 or 24 h previously had decreased to 0% compared with those receiving only M-CSF. The present results suggest that the vitamin K2 "causes cell death" to mature osteoclasts and inhibits in vivo osteoclast formation.
authors.affiliation: Department of Orthodontics, Hiroshima University School of Dentistry, Japan. tenzan@ipc.hiroshima-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Kawata
authors.forename: J H
authors.initials: JH
authors.lastname: Zernik
authors.forename: T
authors.initials: T
authors.lastname: Fujita
authors.forename: C
authors.initials: C
authors.lastname: Tokimasa
authors.forename: K
authors.initials: K
authors.lastname: Tanne
mesh_terms: D000818:Animals; D001862:Bone Resorption; D002452:Cell Count; D016923:Cell Death / Q000187:drug effects; D005260:Female; D006801:Humans; D007700:Kinetics; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D010010:Osteoclasts / Q000187:drug effects / Q000502:physiology*; D010022:Osteopetrosis / Q000503:physiopathology*; D011994:Recombinant Proteins / Q000494:pharmacology; D014812:Vitamin K / Q000494:pharmacology*
chemical_list: D011994:Recombinant Proteins; D014812:Vitamin K; D016173:Macrophage Colony-Stimulating Factor