Vitamin K is no antagonist for the action of warfarin in rat osteosarcoma UMR 106

Thromb Res. 1988 Apr 1;50(1):27-32. doi: 10.1016/0049-3848(88)90171-5.


The recycling of vitamin K in the liver occurs via one or two dithiol-dependent reductases, which are strongly inhibited by coumarin derivatives such as warfarin. This inhibition may be partly overcome by the action of a NADH-dependent reductase, which is relatively insensitive for warfarin. In this paper we demonstrate that the osteoblast-like osteosarcoma UMR 106 does not contain the NADH-dependent reductase. Assuming that a similar enzyme distribution occurs in normal osteoblasts this explains the observation of Price and Kaneda, that the administration of vitamin K to rats efficiently counteracted the effect of warfarin on blood coagulation, but that the vitamin had no effect on the Gla-content of serum osteocalcin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Coagulation / drug effects
  • Carboxy-Lyases / metabolism
  • Liver / enzymology
  • Microsomes / enzymology
  • Osteosarcoma / enzymology*
  • Oxidoreductases / metabolism
  • Rats
  • Rats, Inbred BN
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / enzymology
  • Vitamin K / pharmacology*
  • Warfarin / antagonists & inhibitors*


  • Vitamin K
  • Warfarin
  • Oxidoreductases
  • Carboxy-Lyases