Huber A M, Davidson K W, O'Brien-Morse M E, Sadowski J A
Vitamin K Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
J Nutr. 1999 May;129(5):1039-44. doi: 10.1093/jn/129.5.1039.
Phylloquinone and ten menaquinones (MK-1-MK-10) were measured in liver and eight extrahepatic tissues from male and female rats at 3, 12 and 24 mo of age. Phylloquinone and menaquinones showed characteristic tissue distribution. In liver, all 11 vitamers of vitamin K assayed were present in varying concentrations with phylloquinone and MK-6 the major forms. The only forms of vitamin K found in extrahepatic tissues were phylloquinone, MK-4 and MK-6. Brain contained only MK-4 and traces of phylloquinone. No significant gender difference was observed for phylloquinone except in heart at 3 mo of age (P </= 0.05). In heart, kidney and brain, MK-4 was significantly higher in females than in males (P </= 0.05). A similar gender effect was seen in kidney and lung for MK-6 (P </= 0.05). With age, hepatic phylloquinone and MK-6 significantly increased (P </= 0.05), whereas MK-4 was unchanged. In extrahepatic tissues, MK-4 decreased with age in heart and kidney of males and females, and in lung and cerebellum of males (P </= 0.05). MK-6 decreased with age in all extrahepatic tissued tested (P </= 0.05). The results suggest that in extrahepatic tissues, certain menaquinones may be the predominant form of vitamin K. The specific tissue distribution and the general decline of MK-4 and MK-6 in extrahepatic tissues during aging suggest a vitamin K tissue dynamic that is affected not only by diet, but also by gender, age and the specific roles of phylloquinone, MK-4 and MK-6 in metabolism. All of these factors must be taken into account in establishing the nutrient requirement for vitamin K.
在3、12和24月龄的雄性和雌性大鼠的肝脏以及八个肝外组织中测定了叶绿醌和十种甲基萘醌（MK-1 - MK-10）。叶绿醌和甲基萘醌呈现出特征性的组织分布。在肝脏中，所检测的维生素K的所有11种形式均以不同浓度存在，其中叶绿醌和MK-6为主要形式。在肝外组织中发现的维生素K的唯一形式是叶绿醌、MK-4和MK-6。大脑仅含有MK-4和微量的叶绿醌。除了3月龄时心脏中的叶绿醌外，未观察到明显的性别差异（P≤0.05）。在心脏、肾脏和大脑中，雌性的MK-4显著高于雄性（P≤0.05）。在肾脏和肺中，MK-6也观察到了类似的性别效应（P≤0.05）。随着年龄的增长，肝脏中的叶绿醌和MK-6显著增加（P≤0.05），而MK-4则保持不变。在肝外组织中，雄性和雌性心脏和肾脏以及雄性肺和小脑中的MK-4随年龄下降（P≤0.05）。在所有测试的肝外组织中，MK-6均随年龄下降（P≤0.05）。结果表明，在肝外组织中，某些甲基萘醌可能是维生素K的主要形式。肝外组织中特定的组织分布以及衰老过程中MK-4和MK-6的普遍下降表明，维生素K的组织动态不仅受饮食影响，还受性别、年龄以及叶绿醌、MK-4和MK-6在代谢中的特定作用影响。在确定维生素K的营养需求时，必须考虑所有这些因素。
