Conversion of dietary phylloquinone to tissue menaquinone-4 in rats is not dependent on gut bacteria

J Nutr. 1998 Feb;128(2):220-3. doi: 10.1093/jn/128.2.220.

Abstract

The ability of male rats to accumulate menaquinone-4 (MK-4) in tissues when fed a vitamin K-deficient diet supplemented with intraperitoneal phylloquinone (K) as the sole source of vitamin K for 14 d was assessed. In both conventionally housed controls and gnotobiotic rats, supplementation with the equivalent of 1500 microg vitamin K/kg diet increased (P < 0.001) tissue MK-4 concentrations above those of controls fed a vitamin K-deficient diet. MK-4 concentrations were approximately 5 ng/g (11 pmol/g) in liver, 14 ng/g in heart, 17 ng/g in kidney, 50 ng/g in brain and 250 ng/g in mandibular salivary glands of gnotobiotic rats. MK-4 concentrations in conventionally housed rats were higher than in gnotobiotic rats in heart (P < 0.01), brain (P < 0.01) and kidney (P < 0.05) but lower in salivary gland (P < 0.05). Cultures of a kidney-derived cell line (293) converted K to the expoxide of MK-4 in a manner that was dependent on both time of incubation and concentration of vitamin K in the media. A liver-derived cell line (H-35) was less active in carrying out this conversion. These data offer conclusive proof that the tissue-specific formation of MK-4 from K is a metabolic transformation that does not require bacterial transformation to menadione as an intermediate in the process.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Asepsis
  • Cells, Cultured
  • Diet
  • Humans
  • Injections, Intraperitoneal
  • Intestines / microbiology
  • Kidney / drug effects
  • Kidney / metabolism
  • Liver / drug effects
  • Liver / metabolism
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Vitamin K / administration & dosage
  • Vitamin K / metabolism*
  • Vitamin K 1 / administration & dosage
  • Vitamin K 1 / metabolism*

Substances

  • Vitamin K
  • Vitamin K 1