Vitamin K is no antagonist for the action of warfarin in rat osteosarcoma UMR 106.
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.
Ulrich
M M
MM
Department of Biochemistry, University of Limburg, Maastricht, The Netherlands.
Knapen
M H
MH
Herrmann-Erlee
M P
MP
Vermeer
C
C
D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects; D002262:Carboxy-Lyases / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008861:Microsomes / Q000201:enzymology; D012516:Osteosarcoma / Q000201:enzymology*; D010088:Oxidoreductases / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000201:enzymology; D014812:Vitamin K / Q000494:pharmacology*; D014859:Warfarin / Q000037:antagonists & inhibitors*
D014812:Vitamin K; D014859:Warfarin; D010088:Oxidoreductases; D002262:Carboxy-Lyases