Vitamin K Reversible Hypoprothrombinemia in Rats II. Efficacy of Vitamin K on Latamoxef-Induced Coagulopathy in Rats

Feeding of a vitamin K-deficient diet caused the development of hypo-prothrombinemic changes in rats such as prolongation of prothrombin time (PT) and activated partial thromboplastin time (APTT), decreases in plasma prothrombin and clotting factor VII levels, and an increase in the descarboxyprothrombin (PIVKA) level in both plasma and liver. Successive administrations of latamoxef (LMOX) to the vitamin K-deficient rats resulted in the further enhancement of these changes. After the development of hypoprothrombinemia with LMOX, a single subcutaneous injection of vitamin K1 normalized most of these abnormalities in blood coagulation parameters within 6 hr. When vitamin Κ was given at 200 μg/kg, PT, APTT and the plasma PIVKA level showed normal values for at least 8 days even when the animals were fed a vitamin K-deficient diet and treated with LMOX during the recovery period. The amount of vitamin Κ required to maintain most of the blood coagulation parameters in the normal range was about 3 μg/kg/day. The plasma level of vitamin Κ was higher than 0.3-0.5 ng/ml when the blood coagulation parameters were maintained in the normal range.