title: Menatetrenone prevents osteoblast dysfunction in unilateral sciatic neurectomized rats.
abstract: Menatetrenone (MK-4) inhibits bone resorption and enhances osteoblast-induced mineralization. In this study, we examined whether MK-4 administration had beneficial effects on osteoblast dysfunction and trabecular microstructure as well as on bone volume loss in a rat model of osteopenia. Male Sprague-Dawley rats were neurectomized and administered MK-4 as a daily supplement. On Day 21 after neurectomy, significant bone loss was observed in the positive control rats. MK-4 prevented the decrease in bone mineral density of the distal metaphysis of the femur. The osteoclast surface per bone surface (Oc.S/BS) and the number of osteoclasts per bone perimeter (N.Oc/B.Pm) were reduced and the mineral apposition rate (MAR) decreased in the immobilized rats on Day 42, suggesting suppression of bone turnover. In contrast, administration with a low dose of menatetrenone led to an increase of MAR and bone formation rate (BFR), while Oc.S/BS and N.Oc/B.Pm remained at normal levels. These data suggested that MK-4 reduced the loss of trabecular bone, prevented osteoblast dysfunction to a certain extent, and contributed to preservation of the trabecular microstructure in this rat model of osteopenia induced by sciatic neurectomy.
authors.affiliation: Division of Nephrology, Clinical Research Center, Tokyo Teishin Hospital, Fujimi, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yamato
authors.forename: Hisashi
authors.initials: H
authors.lastname: Murayama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takahashi
authors.forename: Ikuko
authors.initials: I
authors.lastname: Ezawa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kurokawa
authors.forename: Masafumi
authors.initials: M
authors.lastname: Fukagawa
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D001851:Bone Diseases, Metabolic / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D010006:Osteoblasts / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020426:Sciatic Neuropathy / Q000503:physiopathology*; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D024482:Vitamin K 2; C030814:menatetrenone