Inhibition byl-phenylalanine of tryptophan transport by synaptosomal plasma membrane vesicles: Implications in the pathogenesis of phenylketonuria
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Phenylalanine is accumulated in the genetically linked deficiency phenylketonuria. The effect ofl-phenylalanine on the transport of tryptophan was studied using membrane vesicles from rat-brain synaptosomes. Phenylalanine at similar concentrations to those found in phenylketonuric patients competitively inhibits tryptophan uptake, with aKi of the same order as theKm for tryptophan. This inhibition could be responsible for the depletion of serotonin found in phenylketonuria.
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- Barbosa, E., Joanny, P. and Carriol, J. Accumulation active du tryptophane dans le cortex cérébral isolé du rat.C. R. Soc. Biol. (París) 164 (1970) 345–350Google Scholar
- Blau, K. Phenylalanine hydroxylase deficiency: Biochemical, physiological, and clinical aspects of phenylketonuria and related phenylalaninemias. In Youdim, M. B. H. (ed)Aromatic Amino Acid Hydroxylases and Mental Disease, Wiley, New York, NY (1979), pp. 77–139Google Scholar
- Fernston, J. W. and Wurtzman, R. J. Brain serotonin content: physiological dependence on plasma tryptophan levels.Science 173 (1974) 149–152Google Scholar
- Lädhesmäki, P. and Hannus, M.-L. Effect of aromatic acids on the influx of aromatic amino acids in rat brain slices.Exp. Brain. Res. 30 (1977) 539–548Google Scholar
- Lajtha, A. Amino acid transport in the brainin vivo andin vitro. In Wolstenholme, G. E. W. and Fitzsimons, D. W. (eds.)Aromatic Amino Acids in the Brain, Elsevier, Amsterdam, 1974, pp. 25–41Google Scholar
- Mandell, A. J. and Knapp, S. Regulation of serotonin biosynthesis in brain: role of the high affinity uptake of tryptophan into serotonergic neurons.Fed. Proc., Fed. Am. Soc. Exp. Biol. 36 (1977) 2142–2148Google Scholar
- Pratt, O. E. The transport of metabolizable substances into the living brain. In Levi, G., Battistin, L. and Lajtha, A. (eds.)Transport Phenomena in the Nervous System: Physiological and Pathological Aspects. Advances in Experimental Medicine and Biology. Plenum Press, New York, 1976, pp 55–75Google Scholar
- Pratt, O. E. The needs of the brain for amino acids and how they are transported across the blood-brain barrier. In Belton, N. R. and Toothill, C. (eds.)Transport and Inherited Disease. MTP Press, Lancaster, 1981, pp. 87–122Google Scholar