Fluorometric Determination of Phylloquinone and Menaquinone-4 in Biological Materials using High Performance Liquid Chromatography

The placental and mammary transport of (14C) menaquinone-4 in rats.

“…2). We observed rapid intestinal absorption of menaquinone-4 and a quick decline of radioactivity in the blood, similar to the case of phylloquinone in previous studies (8,9) using the normal rat. But intestinal absorption of vitamin K by humans is slower both in the child (10) and in the adult (11)(12)(13) .…”

Vitamin K(1) Diffusion across the Placental Barrier in the Gravid Female Rat

“…By determining vitamin Ki levels directly through an HPLC method, our no decrease in phylloquinone levels of moth ers tested at the end of pregnancy. In the rat, we noted rapid intestinal absorption of vita min Ki after oral administration: 1-2 h, as already mentioned in previous studies using the rat [16,17], Intestinal absorption by hu mans is slower, both in the child [18] and in the adult [19].…”

“…In the gravid and control rats, elimination half-lives were 3.6 and 5.8 h, respectively. These rates of elimi nation are slower than those observed by Wiss and Gloor [16] and Abe and Hiroshima [17], The use of large amounts of vitamin K] in our experiment (5 mg/kg) may account for this discrepancy. We chose to give the ani mals high doses of vitamin in anticipation of significant variations in the fetuses, knowing the high vitamin gradient between mother and fetus [13].…”

A vitamin‐K2‐binding factor secreted from Bacillus subtilis

“…Elution was carried out isocratically with a flow rate of 1.0 ml/min at 50°C. Menaquinone was detected aft& reduction with sodium borohydride [8].…”