title: Inhibitory effect of menaquinone-7 (vitamin K2) on the bone-resorbing factors-induced bone resorption in elderly female rat femoral tissues in vitro.
abstract: The inhibitory effect of menaquinone-7 (MK-7; vitamin K2) on osteoclast-like cell formation and osteoclastic bone resorption in vitro is found (Mol Cell Biochem 228: 39-47, 2001). This study, furthermore, was undertaken to determine the effect of MK-7 on the bone-resorbing factor-induced bone resorption using the femoral-diaphyseal and -metaphyseal tissues obtained from elderly female rats in vitro. Femoral-diaphyseal and -metaphyseal tissues were cultured for 48 h in Dulbecco's modified Eagle's medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The experimental cultures contained MK-7 (10(-7)-10(-5) M). The bone-resorbing factors, parathyroid hormone (1-34) (PTH; 10(-7) M) and prostaglandin E2 (PGE2; 10(-5) M), caused a significant decrease in calcium content in the diaphyseal and metaphyseal tissues. The PTH or PGE2-induced decrease in bone calcium content was completely inhibited in the presence of MK-7 (10(-7)-10(-5) M). In addition, MK-7 (10(-7)-10(-5) M) completely prevented the PTH (10(-7) M)- or PGE2 (10(-5) M)-induced increase in medium glucose consumption and lactic acid production by bone tissues. These results support the view that MK-7 has a direct inhibitory effect on the bone-resorbing factor-induced bone resorption in bone culture using female aged femoral tissues in vitro.
authors.affiliation: Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Shizuoka, Japan. yamaguch@u-shizuoka-ken.ac.jp
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tsukamoto
mesh_terms: D000375:Aging / Q000187:drug effects*; D000818:Animals; D001862:Bone Resorption / Q000188:drug therapy*; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media; D015232:Dinoprostone / Q000494:pharmacology; D005260:Female; D005269:Femur / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006131:Growth Inhibitors / Q000494:pharmacology*; D019344:Lactic Acid / Q000378:metabolism; D010281:Parathyroid Hormone / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D006131:Growth Inhibitors; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D024482:Vitamin K 2; D019344:Lactic Acid; C062629:menaquinone 7; D005947:Glucose; D015232:Dinoprostone; D002118:Calcium