Summary
As requirements for tryptophan for synthesis of protein and 5-hydroxytryptamine were comparable in rat brain, during depletion of tryptophan there could be competition between the two pathways for the amino acid. This implied that tryptophan should be rate-limiting for protein synthesis and this was found in the short term when concentrations of the amino acid were reduced in rats.
Multicompartmental studies of tryptophan and tyrosine in controls and patients subject to unipolar depression defined two main pools of the amino acid provisionally assigned to extracellular and intracellular spaces.
For tyrosine, mean values for the extracellular space were comparable to those of controls. The concentration of tyrosine was low in the intracellular space in both depressed and recovered patients, but the raised fractional clearance rates for this compartment during depression had returned to normal on remission.
Plasma tryptophan concentrations were significantly reduced in depression with intermediate values after recovery. This suggested that the procedure used may have been mildly stressful and that this had evoked an idiosyncratic response to the stress in the depressed patients, which was characterized by inability to maintain concentrations of this amino acid in plasma.
The findings for both amino acids may have a bearing on the aetiology of unipolar affective disorder.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
Blazek, R., Shaw, D. M.: Tryptophan availability and brain protein synthesis. Neuropharmacology (in press).
Coppen, A., Shaw, D. M.: Mineral metabolism in melancholia. Lancet ii, 1439–1444 (1963).
Coppen, A., Shaw, D. M., Malleson, A., Costain, R.: Mineral metabolism in mania. Brit. Med. J. 1, 71–75 (1966).
Coppen, A., Wood, K.: Tryptophan and depressive illness. Psychol. Med. 8, 49–57 (1976).
Green, H., Sawyer, J. L.: Demonstration, characterization and assay procedure of tryptophan hydroxylase in the rat brain. Anal. Biochem. 15, 53–64 (1966).
McMenamy, R. H., Oncley, J. L.: The specific binding of L-tryptophan to serum albumin. J. Biol. Chem. 233, 1436–1447 (1958).
Moir, A. T. B., Eccleston, D. J.: The effect of precursor loading in the cerebral metabolism of 5-hydroxyindoles. J. Neurochem. 15, 1093 to 1108 (1968).
Neckers, L. M., Meek, J. L.: Measurement of 5-HT turnover rate in discrete nuclei of rat brain. Life Sciences 19, 1579–1584 (1976).
Pratt, O. E.: Transport Phenomena in the Nervous System (Levi, G., Battistin, L., Lajtha, A., eds.), pp. 55–75. New York: Plenum Press. 1976.
Riley, G. J., Shaw, D. M.: Total and non-bound tryptophan in unipolar illness. Lancet ii, 1249 (1976).
Riley, G. J., Shaw, D. M.: In preparation (1978).
Shaw, D. M., Tidmarsh, S. F., Johnson, A. L., Michalakeas, A. C., Riley, G. J., Blazek, R., Francis, A. F.: Multicompartmental analysis of amino acids. II. Tryptophan in affective disorders. Psychol. Med. (in press, 1978).
Shaw, D. M., Tidmarsh, S. F., Johnson, A. L., Michalakeas, A. C., Riley, G. J., Blazek, R., Mac Sweeney, D. A., Francis, A. F., Hewland, R.: Multicompartmental analysis of amino acids. III. Tyrosine in affective disorders. Psychol. Med. (in press, 1978).
Sourkes, T. L.: Aromatic amino acids in the brain. In: Ciba Foundation Symposium 22 (new series), pp. 361–380. Amsterdam: Elsevier. 1974.
Wurtman, R. J., Fernstrom, J. D.: Control of brain serotonin by the diet. Adv. in Neurol. 5, 19–29 (1974).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1979 Springer-Verlag Wien
About this paper
Cite this paper
Shaw, D.M., Blazek, R., Tidmarsh, S.F., Riley, G.J., Johnson, A.L., Michalakeas, A. (1979). Distribution of Tryptophan and Tyrosine in Unipolar Affective Disorders as Defined by Multicompartmental Analysis. In: Baumann, P. (eds) Transport Mechanisms of Tryptophan in Blood Cells, Nerve Cells, and at the Blood-Brain Barrier. Journal of Neural Transmission, vol 15. Springer, Vienna. https://doi.org/10.1007/978-3-7091-2243-3_18
Download citation
DOI: https://doi.org/10.1007/978-3-7091-2243-3_18
Publisher Name: Springer, Vienna
Print ISBN: 978-3-7091-2245-7
Online ISBN: 978-3-7091-2243-3
eBook Packages: Springer Book Archive