Abstract
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.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Literature Cited
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.
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.
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.
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.
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.
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.
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.
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.
Eisenstein, A. B. (1962) The effect of pyridoxine deficiency on liver and muscle phosphorylase. Biochim. Biophys. Acta 58, 244–247.
Takami, M., Fujioka, M., Wada, M. and Taguchi, T. (1968) Studies on pyridoxine deficiency in rats. Proc. Soc. Exp. Biol. Med. 129, 110–117.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Lumeng, L. and Li, T.-K. (1974) Vitamin B-6 metabolism in chronic alcohol abuse. J. Clin. Invest. 53, 693–704.
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.
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.
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.
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.
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.
Potera, C., Rose, D. P. and Brown, R. R. (1977) Vitamin B-6 deficiency in cancer patients. Am. J. Clin. Nutr. 30, 1677–1679.
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.
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.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1981 Springer Science+Business Media New York
About this chapter
Cite this chapter
Li, TK., Lumeng, L. (1981). Plasma PLP as Indicator of Nutrition Status: Relationship to Tissue Vitamin B-6 Content and Hepatic Metabolism. In: Leklem, J.E., Reynolds, R.D. (eds) Methods in Vitamin B-6 Nutrition. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-9901-8_15
Download citation
DOI: https://doi.org/10.1007/978-1-4684-9901-8_15
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4684-9903-2
Online ISBN: 978-1-4684-9901-8
eBook Packages: Springer Book Archive