Problems of Forensic Sciences 2008 Vol. 73 (LXXIII) 21-29
CO-METABOLISM OF MENADIONE (VITAMIN K3) AND ETHANOL IN HUMAN LIVER FRACTIONS
Krzysztof TUTAJ, Grzegorz BUSZEWICZ, Grzegorz TERESIŃSKI, Roman MĄDRO
Chair and Department of Forensic Medicine, Medical University, Lublin, Poland
Streszczenie
An experiment was carried out to clarify whether the addition of menadione (i.e. vitamin K3, 2-methyl-1,4-naphthoquinone) to human liver homogenates leads to accelerated oxidation of ethanol (Et-OH) and if so, whether mitochondria and the microsomal ethanol-oxidising system (MEOS) are involved, and whether the acceleration depends on the activity of quinone reductase (QR). The kinetics of ethanol elimination in S0.6 and S9 fractions of human liver homogenates was examined after administration of menadione and Et-OH. The third experimental group was the S9 fraction, in which the MEOS was blocked by 3-amino- 1,2,4-triazole (3AT). The activity of QR was blocked with dicumarol (DIC). Concentrations of Et-OH were determined using headspace gas chromatography (HS-GC) with flame ionisation detector (FID). Results: 1) acceleration of EtOH oxidation by menadione occurs in human liver homogenates. Statistically significant smaller areas under the curve of Et-OH elimination plot (AUC values) were shown. 2) Comparison of AUC values shows that in vitro quinone reductase, mitochondrial NADH: ubiquinone oxidoreductase and MEOS are involved in the vitamin K-accelerated rate of EtOH oxidation. These findings demonstrate that mitochondria, MEOS and also QR activity are involved in the menadione – increased rate of Et-OH oxidation.
Słowa kluczowe
Acceleration of ethanol oxidation; Human liver; Subcellular fractions; Reoxidation of NADH.