Uchida K, Nomura Y, Takase H, Harauchi T, Yoshizaki T, Nakao H
Jpn J Pharmacol. 1986 Jan;40(1):115-22. doi: 10.1254/jjp.40.115.
Feeding of vitamin K-deficient diets or fasting produced vitamin K deficient syndromes in both conventional and germ-free male rats in 3 days, increasing prothrombin time (PT), activated partial thromboplastin time (APTT), plasma and liver descarboxyprothrombin (PIVKA) levels and liver gamma-glutamylcarboxylase activities, but decreasing plasma clotting factor VII and prothrombin levels. These changes were not found when daily 30 micrograms/rat of vitamin K1 was injected during this period. The changes caused by fasting were comparable with those caused by a diet containing 20-30 ng/g of vitamin K1, while a diet containing less than 5 ng/g caused greater changes in both conventional and germ-free rats. Germ-free rats on a diet containing sufficient amounts of vitamin K1 showed PT and APTT values similar to those in conventional rats, but lower plasma clotting factor levels and higher PIVKA and microsomal gamma-glutamylcarboxylase activities. The values for PT, APTT, factor VII, prothrombin and PIVKA in the fasted germ-free rats were almost the same as those in the fasted conventional rats. These findings suggest that menaquinones synthesized in the large intestine are not utilized sufficiently to prevent vitamin K deficiency in rats.
给常规饲养和无菌饲养的雄性大鼠喂食维生素K缺乏饮食或使其禁食3天，会引发维生素K缺乏综合征，表现为凝血酶原时间（PT）延长、活化部分凝血活酶时间（APTT）延长、血浆和肝脏中脱羧凝血酶原（PIVKA）水平升高、肝脏γ-谷氨酰羧化酶活性增强，但血浆凝血因子VII和凝血酶原水平降低。在此期间，若每天给大鼠注射30微克/只的维生素K1，则不会出现这些变化。禁食引起的变化与喂食含20 - 30纳克/克维生素K1的饮食所引起的变化相当，而喂食含低于5纳克/克维生素K1的饮食，在常规饲养和无菌饲养的大鼠中都会引起更大的变化。食用含足量维生素K1饮食的无菌大鼠，其PT和APTT值与常规大鼠相似，但血浆凝血因子水平较低，PIVKA和微粒体γ-谷氨酰羧化酶活性较高。禁食的无菌大鼠的PT、APTT、因子VII、凝血酶原和PIVKA值与禁食的常规大鼠几乎相同。这些发现表明，在大鼠大肠中合成的甲萘醌不能被充分利用以预防维生素K缺乏。
