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Intestinal flora is not an intermediate - Printable Version

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Intestinal flora is not an intermediate - sm1693 - 03-27-2018

I've been looking into how the actual conversion takes place. Still a mystery though.


Intestinal flora is not an intermediate in the phylloquinone-menaquinone-4 conversion in the rat.


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.


RE: Intestinal flora is not an intermediate - ChasingGoodandEvil - 09-30-2018

(03-27-2018, 02:46 AM)sm1693 Wrote: I've been looking into how the actual conversion takes place. Still a mystery though.


Intestinal flora is not an intermediate in the phylloquinone-menaquinone-4 conversion in the rat.


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.
Thats interesting, maybe the bacteria just produce catalysts or precursors for an endogenous reaction


RE: Intestinal flora is not an intermediate - sm1693 - 10-16-2018

I doubt it. My personal experiments show excellent functioning taking in only k1 from greens while doing aggressive antibiotic antifungal measures.