Yamaguchi M, Taguchi H, Gao Y H, Igarashi A, Tsukamoto Y
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
J Bone Miner Metab. 1999;17(1):23-9. doi: 10.1007/s007740050059.
The effect of dietary vitamin K2 (menaquinone-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing menaquinone-4 (MK-4; 12mg/100g diet) or menaquinone-7 (MK-7; 18.1mg/100g diet) for 24 days; MK-4 and MK-7 were equal in molar concentrations. This feeding caused a remarkable increase of MK-4 and MK-7 concentrations in the serum and femur of OVX rats. OVX-induced decrease in the femoral dry weight and femoral calcium content was prevented by the feeding of dietary MK-4 or NK-7. In separate experiments, OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 microg MK-7/100g diet) without or with added MK-7 (37.6 microg/100g diet) for 77 days. Feeding produced a significant elevation of MK-4 and MK-7 concentrations in the serum of OVX rats. In this case, a significant increase in the femoral MK-4 content was observed but MK-7 was not detected in the femoral tissues. OVX-induced decreases in the femoral dry weight and femoral calcium content were significantly prevented by the feeding of diets containing natto with MK-7 added (37.6 microg/100g diets). This study demonstrates that the intake of dietary MK-7 has a preventive effect on bone loss caused by OVX. This effect may be partly caused by MK-4, which is formed by degradation of MK-7.
研究了膳食维生素K2（甲萘醌-7）对去卵巢（OVX）大鼠骨质流失的影响。给OVX大鼠自由提供含甲萘醌-4（MK-4；12mg/100g饲料）或甲萘醌-7（MK-7；18.1mg/100g饲料）的实验饲料，持续24天；MK-4和MK-7的摩尔浓度相等。这种喂养方式使OVX大鼠血清和股骨中的MK-4和MK-7浓度显著增加。通过喂食膳食MK-4或NK-7可防止OVX诱导的股骨干重和股骨钙含量降低。在单独的实验中，给OVX大鼠自由提供含发酵大豆（纳豆；含9.4μg MK-7/100g饲料）且添加或不添加MK-7（37.6μg/100g饲料）的实验饲料，持续77天。喂食使OVX大鼠血清中的MK-4和MK-7浓度显著升高。在这种情况下，观察到股骨中MK-4含量显著增加，但在股骨组织中未检测到MK-7。通过喂食添加了MK-7（37.6μg/100g饲料）的纳豆饲料，可显著防止OVX诱导的股骨干重和股骨钙含量降低。本研究表明，摄入膳食MK-7对OVX引起的骨质流失具有预防作用。这种作用可能部分由MK-7降解形成的MK-4引起。
