Plasma PLP as Indicator of Nutrition Status: Relationship to Tissue Vitamin B-6 Content and Hepatic Metabolism

  • Ting-Kai Li
  • Lawrence Lumeng


In assessment of nutritional status, diagnostic indicators should correlate in a well-defined manner not only with tissue content but also with the functional adequacy of the substance in question. Ideally, they would measure undernutrition as well as storage capacity. It is fortunate in the instance of vitamin B-6 that both the storage and the coenzyme (functional) forms are the same compounds, viz., the phosphorylated derivatives, pyridoxal phosphate (PLP) and pyridoxamine phosphate (PMP). These coenzyme forms are interconvertible via transamination reactions, but different tissues and body fluid compartments contain different amounts and ratios of PLP and PMP, presumedly reflecting regional peculiarities and dependence for the function of certain PLP-specific enzymes and binding proteins. Accordingly, if plasma PLP concentration is to serve as a diagnostic indicator, its relationship to the PLP (and PMP) content of tissues and to the activities of representative PLP-dependent enzymes must be delineated under conditions of both vitamin B-6 deficiency and excess. Furthermore, because the liver is the principal, if not the sole, organ that supplies blood plasma with PLP (1), the dependence of PLP and other B-6 vitamers in plasma upon hepatic metabolism needs to be understood. This communication summarizes recent studies from our laboratory and those of others that address these issues.


Celiac Disease Glycogen Phosphorylase Human Blood Plasma Pyridoxal Phosphate Pyridoxine Deficiency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Literature Cited

  1. 1.
    Lumeng, L., Brashear, R. E. and Li, T.-K. (1974) Pyridoxal 5’-phosphate in plasma. Source, protein-binding, and cellular transport. J. Lab. Clin. Med. 84, 334–343.Google Scholar
  2. 2.
    Bain, J. A. and Williams, H. L. 1960 ) Concentrations of B-6 vitamers in tissues and tissue fluids. In: Inhibition in the Nervous System and Gamma-aminobutyric Acid. ( Roberts, E, Baxter, C. F., Harreveld, A. V., Wiersma, C.A.G., Adey, W. R. and Killam, K. F., eds.) Pergamon Press, New York, NY.Google Scholar
  3. 3.
    Lyon, J. B., Jr., Bain, J. A. and Williams, H. L. (1962) The distribution of vitamin B-6 in the tissues of two inbred strains of mice fed complete and vitamin B-6-deficient rations. J. Biol. Chem. 237, 1989–1991.Google Scholar
  4. 4.
    Bell, R. R. and Haskell, B. E. (1971) Metabolism of vitamin B-6 in the I-strain mouse. I. Absorption, excretion, and conversion of vitamin to enzyme co-factor. Arch. Biochem. Biophys. 147, 588–601.CrossRefGoogle Scholar
  5. 5.
    Lumeng, L., Ryan, M. P. and Li, T.-K. (1978) Validation of the diagnostic value of plasma pyridoxal 5’-phosphate measurements in vitamin B-6 nutrition of the rat. J. Nutr. 108, 545–553.Google Scholar
  6. 6.
    Black, A. L., Guirard, B. M. and Snell, E. E. (1977) Increased muscle phosphorylase in rats fed high levels of vitamin B-6. J. Nutr. 107, 1962–1968.Google Scholar
  7. 7.
    Bosron, W. F., Veitch, R. L., Lumeng, L. and Li, T.-K. (1978) Subcellular localization and identification of pyridoxal 5’phosphate-binding proteins in rat liver. J. Biol. Chem. 253, 1488–1492.Google Scholar
  8. 8.
    Illingworth, B., Kornfeld, R. and Brown, D. H. (1960) Phos- phorylase and uridine diphospho-glucose-glycogen transferase in pyridoxine deficiency. Biochim. Biophys. Acta 42, 486–489.Google Scholar
  9. 9.
    Eisenstein, A. B. (1962) The effect of pyridoxine deficiency on liver and muscle phosphorylase. Biochim. Biophys. Acta 58, 244–247.CrossRefGoogle Scholar
  10. 10.
    Takami, M., Fujioka, M., Wada, M. and Taguchi, T. (1968) Studies on pyridoxine deficiency in rats. Proc. Soc. Exp. Biol. Med. 129, 110–117.Google Scholar
  11. 11.
    Black, A. L., Guirard, M. B. and Snell, E. E. (1978) The behavior of muscle phosphorylase as a reservoir for vitamin B-6 in the rat. J. Nutr. 108, 670–677.Google Scholar
  12. 12.
    Lumeng, L., Lui, A. and Li, T.-K. (1980) Plasma content of B-6 vitamers and its relationship to hepatic vitamin B-6 metabolism. J. Clin. Invest. 66, 688–695.CrossRefGoogle Scholar
  13. 13.
    Li, T.-K., Lumeng, L. and Veitch, R. L. (1974) Regulation of pyridoxal 5’-phosphate metabolism in liver. Biochem. Biophys. Res. Commun. 61, 667–684.CrossRefGoogle Scholar
  14. 14.
    Baysal, A., Johnson, B. A. and Linkswiler, H. (1966) Vitamin B-6 depletion in man. Blood vitamin B-6, plasma pyridoxalphosphate, serum cholesterol, serum transaminases, and urinary vitamin B-6 and 4-pyridoxic acid. J. Nutr. 89, 19–23.Google Scholar
  15. 15.
    Hamfelt, A. (1967) Enzymatic determination of pyridoxal phosphate in plasma by decarboxylation of L-tyrosine- C(U) and a comparison with the tryptophan load test. Scand. J. Clin. Lab. Invest. 20, 1–10.Google Scholar
  16. 16.
    Chabner, B. A., DeVita, V. T., Livingston, D. M. and Oliverio, V. T. (1970) Abnormalities of tryptophan metabolism and plasma pyridoxal phosphate in Hodgkin’s disease. New Eng. J. Med. 282, 838–843.CrossRefGoogle Scholar
  17. 17.
    Sauberlich, H. E., Canham, J. E., Baker, E. M., Raica, N., Jr. and Herman, Y. F. (1972) Biochemical assessment of the nutritional status of vitamin B-6 in the human. Am. J. Clin. Nutr. 25, 629–642.Google Scholar
  18. 18.
    Brown, R. R., Rose, D.P., Leklem, J. E., Linkswiler, H. and Anand, R. (1975) Urinary pyridoxic acid, plasma pyridoxal phosphate, and erythrocyte aminotransferase levels in oral contraceptive users receiving controlled intakes of vitamin B-6. Am. J. Clin. Nutr. 28, 10–19.Google Scholar
  19. 19.
    Lumeng, L., Cleary, R. E. and Li, T.-K. (1974) Effect of oral contraceptives,on the plasma concentration of pyridoxal phosphate. Am. J. Clin. Nutr. 27, 326–333.Google Scholar
  20. 20.
    Mitchell, D., Wagner, C., Stone, W. J., Wilkinson, G. R. and Schenker, S. (1976) Abnormal regulation of plasma pyridoxal 5’-phosphate in patients with liver disease. Gastroenterology 71, 1043–1049.Google Scholar
  21. 21.
    Lumeng, L. and Li, T.-K. (1974) Vitamin B-6 metabolism in chronic alcohol abuse. J. Clin. Invest. 53, 693–704.CrossRefGoogle Scholar
  22. 22.
    Rose, C. S., György, P., Butler, M., Andres, R., Norris, A. H., Shock, N. W., Tobin, J., Brin, M. and Spiegel, H. (1976) Age differences in vitamin B-6 status of 617 men. Am. J. Clin. Nutr. 29, 847–853.Google Scholar
  23. 23.
    Cleary, R. E., Lumeng, L. and Li, T.-K. (1975) Maternal and fetal plasma levels of pyridoxal phosphate at term: adequacy of vitamin B-6 supplementation during pregnancy. Am. J. Obstet. Gynecol. 121, 25–28.Google Scholar
  24. 24.
    Lumeng, L., Cleary, R. E., Wagner, R., Yu, P. L. and Li, T.-K. (1976) Adequacy of vitamin B-6 supplementation during pregnancy: a prospective study. Am. J. Clin. Nutr. 29, 1376–1383.Google Scholar
  25. 25.
    Labadarios, D., Rossouw, J. E., McConnell, J. B., Davis, M. and Williams, R. (1977) Vitamin B-6 deficiency in chronic liver disease–evidence for increased degradation of pyridoxal 5’-phosphate. Gut 18, 23–27.CrossRefGoogle Scholar
  26. 26.
    Spannuth, C. L., Jr., Warnock, L. G., Wagner, C. and Stone, W. J. (1977) Increased plasma clearance of pyridoxal 5’-phosphate in vitamin B-6-deficient uremic man. J. Lab. Clin. Med. 90, 632–637.Google Scholar
  27. 27.
    Potera, C., Rose, D. P. and Brown, R. R. (1977) Vitamin B-6 deficiency in cancer patients. Am. J. Clin. Nutr. 30, 1677–1679.Google Scholar
  28. 28.
    Reinken, L., Zieglauer, H. and Berger, H. (1976) Vitamin B-6 nutriture of children with acute celiac disease, celiac disease in remission and of children with normal duodenal mucosa. Am. J. Clin. Nutr. 29, 750–753.Google Scholar
  29. 29.
    Teehan, B. P., Smith, L. J., Sigler, M. H., Gilgore, G. S. and Schleifer, C. R. (1978) Plasma pyridoxal phosphate levels and clinical correlations in chronic hemodialysis patients. Am. J. Clin. Nutr. 31, 1932–1936.Google Scholar

Copyright information

© Springer Science+Business Media New York 1981

Authors and Affiliations

  • Ting-Kai Li
    • 1
  • Lawrence Lumeng
    • 1
  1. 1.VA Medical Center & Departments of Medicine and BiochemistryIndiana University School of MedicineIndianapolisUSA

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