Abstract
The anticoagulant effects of potassium warfarin and the antagonistic effects of vitamin K3 against warfarin were examined in the common carp. Warfarin (1.0mg/kg/day) with and without vitamin K3 was orally administered to the common carp for 35 days, and prothrombin time (PT), Russell's viper venom time (RVVT) and the absorbance of the chromogenic substrate assay (CSA) using S-2337 were measured at intervals of 7 days. Prolongation of PT and RVVT, and a decrease in the absorbance in the CSA were observed after the oral administration of warfarin, indicating that both activities of the extrinsic and common pathways were affected. Supplementation with vitamin K3 (0.1mg/kg/day) was effective in preventing the prolongation of PT and RVVT, but the decrease in theabsorbance in the CSA was not prevented. These findings suggest the existence of vitamin K-dependent factors involved in both the extrinsic and common pathways.
