Vitamin K (Menaquinone-4) Metabolism in Liver Disease

Abstract

We measured menaquinone-4 (MK-4) and MK-4 epoxide concentrations in plasma and liver tissue after intravenous injection of 200 micrograms/kg MK-4 in 42 patients who underwent hepatectomy. They were classified into normal (N; n = 10), chronic hepatitis (CH; n = 12), and liver cirrhosis (LC; n = 20) groups, on the basis of the diagnosis given by the pathologist after examining resected liver specimens. The plasma MK-4 epoxide concentration reached maximum level (Cmax) 60 min after MK-4 injection. The Cmax in groups LC and CH were 85.9 and 126.3 nmol/l, respectively, which is significantly reduced compared with that of group N (184.4 nmol/l) (p less than 0.01 and p less than 0.05, respectively). The MK-4 concentrations in liver tissues of 24 patients 60 min after MK-4 injection were 2.77 in group N, 3.79 in group CH, and 3.83 nmol/g in group LC, and the MK-4 epoxide concentrations were 4.01, 3.09, and 2.62 nmol/g in the respective groups. Consequently, the ratio of MK-4 epoxide to total MK-4 (MK-4 + MK-4 epoxide) in groups CH and LC was significantly lower than in group N (p less than 0.01). It is concluded that the Cmax of MK-4 epoxide after MK-4 injection may serve as an indicator of liver function and that the low ratio of MK-4 epoxide to total MK-4 in the liver shows impairment in vitamin K metabolism.

Diagnostic accuracy of α‐fetoprotein and des‐γ‐carboxy prothrombin in screening for hepatocellular carcinoma in liver transplant candidates

“…However, no data to date suggest the use of DCP during pre‐transplantation screening or diagnosis. Level of DCP in patients with severe liver impairment may be increased due to altered vitamin K metabolism such as obstructive jaundice or wide‐spectrum antibiotics use 19–23 . If DCP levels often increase false‐positively due to causes other than HCC, diagnostic accuracy of DCP will be reduced.…”

Effect of oil-in-water lipid emulsions prepared with fish oil or soybean oil on the growth of MCF-7 cells and HepG2 cells

“…Therefore, menatetrenone would also be retained inside the lipid particles during in-vitro experiments and would be a suitable marker for determining the cellular uptake of the particles. Since menatetrenone is a cofactor for g-glutamyl carboxylase and is easily converted into menatetrenone epoxide in the liver (Nishimura et al 1990;Suhara et al 2006), we considered it necessary to examine the level of menatetrenone epoxide as well. Another hypothesis is the peroxidation due to n-3 FAs; eicosapentaenoic acid (EPA) and docosahexaenoic acid, two major n-3 FAs, are readily oxidized in the presence of free radicals because they have additional carbon-carbon double bonds compared with other FAs (Yin et al 2007).…”