LEVELS OF VITAMIN K3 IN HEALTHY VOLUNTEERS AND IN PATIENTS WITH DIFFERENT TYPES OF STOMACH CANCER AFTER A SINGLE VITAMIN K3 ADMINISTRATION

A reversed-phase HPLC method for determining vitamin K-3 in human plasma was developed and validated. Following liquidliquid extraction that converted the MSB to MN with Na2CO3, the MN and internal standard were separated with gradient elution on a reverse-phase C-8 column using a mobile phase of methanol and water. The calibration was linear in the range 0.0303.050 mu g/mL. The intra-day and inter-day precision was lower than 8.36% and 6.74%, respectively. Vitamin K-3 level as MN that is converted from MSB and metabolized MN (if available) were measured in plasma samples obtained from 6 healthy volunteers and 12 stomach cancer patients at different times following the intravenous administration of a single 40mg dose of MSB. There is not a statistically significant increase between plasma vitamin K-3 concentrations with increasing times in both the healthy volunteers and stomach cancer patients. In addition, we compared the plasma vitamin K-3 concentrations in the healthy volunteers and the stomach cancer patients at 3, 5, and 10min and plasma vitamin K-3 concentrations were significantly lower in intestinal and diffuse type's stomach cancer patients than in healthy volunteers at 10min.