Anti-oxidant/pro-oxidant reactions of vitamin K.
Experiments were designed to measure O2 consumption caused by the oxidation of linoleic acid. These experiments show that vitamin K has antioxidant activity and that the reduction in linoleic acid oxidation is directly dependent upon vitamin K concentration. Conversely, vitamin K hydroquinone enhances linoleic acid oxidation in the absence of iron catalyst, again in a concentration dependent manner. At equilmolar concentrations vitamin K is about 80% as effective as vitamin E as an antioxidant. Vitamin E inhibits the oxidation of linoleic acid catalyzed by vitamin K hydroquinone. Vitamin E also strongly inhibits vitamin K dependent formation of both vitamin K epoxide and gamma-carboxyglutamic acid (gla). The significance of these observations to vitamin K action in vivo is discussed.
D000818:Animals; D019735:Carbon-Carbon Ligases; D004305:Dose-Response Relationship, Drug; D004852:Epoxy Compounds / Q000378:metabolism; D008025:Ligases / Q000037:antagonists & inhibitors; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008297:Male; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains; D014810:Vitamin E / Q000494:pharmacology; D014812:Vitamin K / Q000378:metabolism*; D010837:Vitamin K 1 / Q000031:analogs & derivatives / Q000378:metabolism
D004852:Epoxy Compounds; D008041:Linoleic Acids; D014812:Vitamin K; D014810:Vitamin E; C028843:vitamin K1 hydroquinone; D010837:Vitamin K 1; D019787:Linoleic Acid; D008025:Ligases; D019735:Carbon-Carbon Ligases; C020660:glutamyl carboxylase