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Tryptophan metabolism in vitamin B6-deficient mice

Published online by Cambridge University Press:  09 March 2007

David A. Bender ,
Eliud N. M. Njagi  and
Paul S. Danielian
David A. Bender
Affiliation:
Department of Biochemistry, University College and Middlesex School of Medicine, University College London, Gower Street, London WCIE 6BT
Eliud N. M. Njagi
Affiliation:
Department of Biochemistry, University College and Middlesex School of Medicine, University College London, Gower Street, London WCIE 6BT
Paul S. Danielian
Affiliation:
Department of Biochemistry, University College and Middlesex School of Medicine, University College London, Gower Street, London WCIE 6BT
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Abstract

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Vitamin B6 deficiency was induced in mice by maintenance for 4 weeks on a vitamin B6-free diet. Tryptophan metabolism was assessed by determining the urinary excretion of tryptophan metabolites, the metabolism of [14C]tryptophan in vivo and the formation of tryptophan and niacin metabolites by isolated hepatocytes. The vitamin B6-deficient animals excreted more xanthurenic acid and 3-hydroxykynurenine, and less of the niacin metabolites N1-methyl nicotinamide and methyl-2-pyridone-4-carboxamide, than did control animals maintained on the same diet supplemented with 5 mg vitamin B6/kg. After intraperitoneal injection of [14C]tryptophan, vitamin B6-deficient mice showed lower liberation of14CO2 from [methylene-14C]tryptophan and [U-14C]tryptophan than did controls, indicating impairment of kynureninase (EC 3.7.1.3) activity. There was no difference between the two groups of animals in the metabolism of [ring-2-14C]tryptophan. Hepatocytes isolated from the vitamin B6-deficient animals formed more 3-hydroxykynurenine and xanthurenic acid than did cells from control animals, but also formed more NADP and free niacin.

Keywords

Tryptophan metabolismVitamin B6 deficiencyMice
Type
Amino acid Metabolism
Information
British Journal of Nutrition , Volume 63 , Issue 1 , January 1990 , pp. 27 - 36
Copyright
Copyright © The Nutrition Society 1990

References

REFERENCES

Allegri, G., Costa, C. & de Antoni, A. (1978). A further contribution to the choice of the dose for tryptophan load test. Acta Vitaminologica Enzymologica (Milan) 32, 163–166.Google Scholar
Bender, D.A. (1980). Inhibition in vitro of the enzymes of the oxidative pathway of tryptophan metabolism and nicotinamide nucleotide synthesis by Benserazide, Carbidopa and isoniazid. Biochemical Pharmacology 29, 707–712.CrossRefGoogle ScholarPubMed
Bender, D.A. (1983 a). Effects of a dietary excess of leucine on the metabolism of tryptophan in the rat: a mechanism for the pellagragenic action of leucine. British Journal of Nutrition 50, 25–32.CrossRefGoogle Scholar
Bender, D.A. (1983 b). Effects of oestradiol and vitamin B6 on tryptophan metabolism in the rat: implications for the interpretation of the tryptophan load test for vitamin B6 nutritional status. British Journal of Nutrition 50, 33–42.CrossRefGoogle ScholarPubMed
Bender, D.A. (1987). Oestrogens and vitamin B6: actions and interactions. World Review of Nutrition and Dietetics 51, 140–188.Google Scholar
Bender, D.A., Gartey-Sam, K., & Singh, A. (1989). Effects of vitamin B6 deficiency and repletion on the uptake of steroid hormones into uterus slices and isolated liver cells of rats. British Journal of Nutrition 61, 619–628.CrossRefGoogle ScholarPubMed
Bender, D.A. & McCreanor, G.M. (1985). Kynurenine hydroxylase: a potential rate-limiting enzyme in tryptophan metabolism. Biochemical Society Transactions 13, 441–443.CrossRefGoogle ScholarPubMed
Bender, D.A. & Olufunwa, R. (1988). Utilization of tryptophan, nicotinamide and nicotinic acid as precursors for nicotinamide nucleotide synthesis in isolated rat liver cells. British Journal of Nutrition 59, 279–287.CrossRefGoogle ScholarPubMed
Bender, D.A., Tagoe, C.E. & Vale, J.A. (1982). Effects of oestrogen administration on vitamin B6 and tryptophan metabolism in the rat. British Journal of Nutrition 47, 609–614.CrossRefGoogle ScholarPubMed
Bender, D.A. & Wynick, D. (1981). Inhibition of kynureninase by oestrone sulphate: an alternative explanation for abnormal results of tryptophan load tests in women receiving oestrogenic steroids. British Journal of Nutrition 45, 269–275.Google Scholar
Bowden, J.-F., Bender, D.A., Coulson, W.F. & Symes, E.K. (1986). Increased uterine uptake and nuclear retention of [3H]oestradiol through the oestrous cycle and enhanced end-organ sensitivity to oestrogen stimulation in vitamin B6 deficient rats. Journal of Steroid Biochemistry 25, 359–365.CrossRefGoogle ScholarPubMed
Carpenter, K. & Kodicek, E. (1950). The fluorimetric estimation of N1-methyl nicotinamide and its differentiation from coenzyme I. Biochemical Journal 46, 421–426.CrossRefGoogle Scholar
Coon, W.W. & Nagler, E. (1969). The tryptophan load test for pyridoxine deficiency in hospitalized patients. Annals of the New York Academy of Sciences 166, 30–43.Google Scholar
Coursin, D.B. (1964). Recommendations for standardization of the tryptophan load test. American Journal of Clinical Nutrition 14, 56–61.Google Scholar
Denckla, W.D. & Dewey, H.K. (1967). The determination of tryptophan in plasma, liver and urine. Journal of Laboratory and Clinical Medicine 69, 160–169.Google Scholar
Holman, W.I.M. (1954). A colorimetric method for the determination of the principal metabolites of nicotinic acid in human urine. Biochemical Journal 56, 513–520.CrossRefGoogle ScholarPubMed
Ikeda, M., Tsuji, H., Nakamura, S., Ichiyama, A., Nishizuka, Y. & Hayaishi, O. (1965). Studies on the biosynthesis of nicotinamide adenine dinucleotide. 2. A role of picolinic carboxylase in the biosynthesis of nicotinamide adenine dinucleotide from tryptophan in mammals. Journal of Biological Chemistry 240, 1395–1401.Google Scholar
Joseph, M.H. & Risby, D. (1975). The determination of kynurenine in plasma. Clinica Chimica Acta 63, 197–204.CrossRefGoogle ScholarPubMed
Knox, W.E. (1953). The relation of liver kynureninase to tryptophan metabolism in pyridoxine deficiency. Biochemical Journal 53, 379–385.CrossRefGoogle ScholarPubMed
Lepkovsky, S. & Nielson, E. (1942). A green pigment-producing compound in urine of pyridoxine deficient rats. Journal of Biological Chemistry 144, 135–138.CrossRefGoogle Scholar
Lepkovsky, S., Roboz, E. & Haagen-Smit, A. J. (1943). Xanthurenic acid and its role in the tryptophane metabolism of pyridoxine deficient rats. Journal of Biological Chemistry 149, 195–201.CrossRefGoogle Scholar
Mehler, A.H., Yano, K. & May, E.L. (1964). Nicotinic acid biosynthesis: control by an enzyme that competes with a spontaneous reaction. Science 145, 817–819.Google Scholar
Salter, M., Knowles, R.G. & Pogson, C.I. (1986). Quantification of the importance of individual steps in the control of aromatic amino acid metabolism. Biochemical Journal 234, 635–647.Google Scholar
Satoh, K. & Price, J.M. (1958). Fluorimetric determination of kynurenic acid and xanthurenic acid in human urine. Journal of Biological Chemistry 230, 781–789.CrossRefGoogle Scholar
Schuster, L., Bates, A. & Hirsch, C.A. (1978). A sensitive radiochemical assay for serum glutamic-oxaloacetic transaminase. Analytical Biochemistry 86, 648–654.Google Scholar
Stanley, J.C., Salter, M., Fisher, M.J. & Pogson, C.I. (1985). The effect of pyridoxine deficiency on the metabolism of the aromatic amino acids by isolated rat liver cells. Archives of Biochemistry and Biophysics 240, 792–800.CrossRefGoogle Scholar
Symes, E.K., Bender, D.A., Bowden, J.-F. & Coulson, W.F. (1984). Increased target tissue uptake of, and sensitivity to, testosterone in the vitamin B6 deficient rat. Journal of Steroid Biochemistry 20, 1089–1093.CrossRefGoogle ScholarPubMed
Watanabe, M., Watanabe, Y. & Okada, M. (1970). A new fluorimetric method for the determination of 3- hydroxykynurenine. Clinica Chimica Acta 27, 461–466.CrossRefGoogle ScholarPubMed