title: Gender differences in hepatic phylloquinone and menaquinones in the vitamin K-deficient and -supplemented rat.
abstract: Gender differences in relation to vitamin K were investigated in the rat. Hepatic phylloquinone and menaquinone (MK-1 to MK-10) concentrations, gamma-carboxyglutamic acid (Gla) excretion, plasma phylloquinone and percent prothrombin were measured in male and female rats on a chow diet (24.5 ng phylloquinone and 8.8 microgram menadione), and on phylloquinone-deficient and -supplemented purified diets (0.38 and 1400 ng phylloquinone/g, respectively). Mean hepatic phylloquinone concentrations varied with dietary intake and ranged from 6.8+/-9.0 pmol/g in the deficient male, to 171. 1+/-56.9 pmol/g in the supplemented female. Menaquinones accounted for a large proportion of total vitamin K in the liver of males and females with MK-4, MK-6, and MK-10 present in highest concentrations. On the chow and supplemented diets, females had significantly higher MK-4, MK-6, and MK-10 concentrations in their livers (P<0.05). On the phylloquinone-deficient diet (-K1), hepatic phylloquinone, MK-4, and to a lesser extent MK-6 (but not MK-10) were significantly reduced (P<0.05). In the phylloquinone-supplemented male and female groups, which did not receive menadione during the experimental period, MK-4 increased above that in the chow groups suggesting synthesis of MK-4 from phylloquinone which was statistically significant in the female (P<0.01). A significant gender difference (P<0.05) was also observed for urinary Gla excretion with less Gla excreted by the females indicating that females may require less dietary phylloquinone than males of the same body weight.
authors.affiliation: Vitamin K Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, 711 Washington St., Boston, MA 02111, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Huber
authors.forename: K W
authors.initials: KW
authors.lastname: Davidson
authors.forename: M E
authors.initials: ME
authors.lastname: O'Brien-Morse
authors.forename: J A
authors.initials: JA
authors.lastname: Sadowski
mesh_terms: D015055:1-Carboxyglutamic Acid / Q000652:urine; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008297:Male; D011516:Prothrombin / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012737:Sex Factors; D014812:Vitamin K / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology*; D010837:Vitamin K 1 / Q000097:blood / Q000172:deficiency / Q000378:metabolism*; D024482:Vitamin K 2 / Q000031:analogs & derivatives; D014813:Vitamin K Deficiency / Q000378:metabolism*
chemical_list: D024482:Vitamin K 2; D014812:Vitamin K; C030814:menatetrenone; D015055:1-Carboxyglutamic Acid; C042455:menaquinone 6; D010837:Vitamin K 1; D011516:Prothrombin