A simple high-performance liquid chromatography (HPLC) method for the measurement of pyridoxal-5-phosphate and 4-pyridoxic acid in human plasma

作者：Cabo Rona; Kozik Karolina; Milanowski Maciej; Hernes Sigrunn; Slettan Audun; Haugen Margaretha; Ye Shu; Blomhoff Rune; Mansoor M Azam^*

来源：Clinica Chimica Acta, 2014, 433: 150-156.

DOI：10.1016/j.cca.2014.03.003

• HPLC
• Vitamin B-6
• PLP and 4-PA

Background: Low concentration of plasma pyridoxal-5-phosphate (PLP) is associated with hyperhomocysteinemia and inflammation. Most methods for the measurement of plasma PLP require large specimen volume and involve the use of toxic reagents.
Methods: We have developed a HPLC method for the measurement of PLP and 4-pyridoxic acid (4-PA) in plasma, which requires small specimen volume. The samples are prepared without adding any toxic reagents. Furthermore, we have examined whether intake of vitamin B-6 affects the concentration of plasma PLP and 4-PA.
Results: The coefficient of variation of the method was 6% and the recovery of the added vitamin in plasma was about 100%. The concentrations of plasma PLP and 4-PA in 168 healthy subjects were 40.6 (8.4-165.0) nmol/L, median and (range) and 17.5 (3.7-114.79) nmol/L, median and (range) respectively. In the multiple regression analyses, the concentration of plasma PLP was associated with the concentration of plasma 4-PA (p < 0.0001), BMI, (p = 0.02) and sex, (p = 0.0008). The concentration of plasma 4-PA was associated with plasma PLP (p < 0.0001), serum folate (p = 0.004), smoking (p = 0.03) and vitamin B-6 intake (p = 0.01).
Conclusion: The present method is suitable for large clinical studies for the measurement of plasma PLP and 4-PA. Our findings demonstrate that plasma 4-PA, BMI and sex are the major determinants of plasma PLP in healthy individuals.

• 出版日期2014-6-10