Ikeda Saiko, Nomura Saki, Hanzawa Fumiaki, Takahashi Saki, Oda Hiroaki, Fujiwara Yoko, Uchida Tomono
Department of Nutritional Sciences, Nagoya University of Arts and Sciences.
Department of Applied Molecular Biosciences, Nagoya University.
J Nutr Sci Vitaminol (Tokyo). 2018;64(4):243-250. doi: 10.3177/jnsv.64.243.
Previous studies have shown that α-tocopherol intake lowers phylloquinone (PK) concentration in some extrahepatic tissues in rats. The study's aim was to clarify the effect of α-tocopherol intake on vitamin K concentration in bone, as well as the physiological action of vitamin K. Male Wistar rats were divided into 4 groups. Over a 3-mo period, the K-free group was fed a vitamin K-free diet with 50 mg RRR-α-tocopherol/kg, the E-free group was fed a diet containing 0.75 mg PK/kg without vitamin E, the control group was fed a diet containing 0.75 mg PK/kg with 50 mg RRR-α-tocopherol/kg, and the E-excess group was fed a diet containing 0.75 mg PK/kg with 500 mg RRR-α-tocopherol/kg. PK concentration in the liver was higher in E-excess rats than in E-free rats, was lower in the tibias of control rats than in those of E-free rats, and was lower in E-excess rats than in control rats. Menaquinone-4 (MK-4) concentration in the liver was higher in E-excess rats than in E-free and control rats. However, MK-4 concentrations in the tibias of E-free, control, and E-excess rats were almost the same. Blood coagulation activity was lower in K-free rats than in the other rats but was not affected by the level of α-tocopherol intake. Additionally, dietary intake of PK and α-tocopherol did not affect uncarboxylated-osteocalcin concentration in the serum, femur density, or expression of the genes related to bone resorption and formation in the femur. These results suggest that α-tocopherol intake decreases PK concentration in bone but does not affect bone metabolism in rats.
先前的研究表明，摄入α-生育酚会降低大鼠某些肝外组织中的叶绿醌（PK）浓度。该研究的目的是阐明摄入α-生育酚对骨骼中维生素K浓度的影响以及维生素K的生理作用。雄性Wistar大鼠被分为4组。在3个月的时间里，无K组喂食不含维生素K但含有50 mg RRR-α-生育酚/千克的饲料，无E组喂食含有0.75 mg PK/千克但不含维生素E的饲料，对照组喂食含有0.75 mg PK/千克和50 mg RRR-α-生育酚/千克的饲料，高E组喂食含有0.75 mg PK/千克和500 mg RRR-α-生育酚/千克的饲料。高E组大鼠肝脏中的PK浓度高于无E组大鼠，对照组大鼠胫骨中的PK浓度低于无E组大鼠，且高E组大鼠低于对照组大鼠。高E组大鼠肝脏中的甲萘醌-4（MK-4）浓度高于无E组和对照组大鼠。然而，无E组、对照组和高E组大鼠胫骨中的MK-4浓度几乎相同。无K组大鼠的血液凝固活性低于其他大鼠，但不受α-生育酚摄入量的影响。此外，饮食中PK和α-生育酚的摄入量不影响血清中未羧化骨钙素的浓度、股骨密度或股骨中与骨吸收和形成相关基因的表达。这些结果表明，摄入α-生育酚会降低骨骼中的PK浓度，但不影响大鼠的骨代谢。
