Neuroendocrine Responses to L-Tryptophan as an Index of Brain Serotonin Function: Effect of Weight Loss

  • I. Anderson
  • P. Cowen
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 294)


Over the last two decades the relationship between plasma tryptophan (TRP) and brain serotonin (5-hydroxytryptamine, 5-HT) synthesis and function has been extensively investigated and many of the factors influencing the transport of TRP into the brain have been elucidated. This is of particular relevance in psychiatry because of longstanding interest in the involvement of 5-HT in processes such as the control of appetite and macronutrient selection, mood and sleep. If physiological alterations in plasma TRP can result in altered brain 5-HT function, this is of potential etiological and therapeutic importance in psychiatric conditions such as depression and eating disorders.


Eating Disorder Thyrotropin Release Hormone Growth Hormone Response Prolactin Secretion Female Volunteer 
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  1. Anderson, I.M., and Cowen, P.J., 1986, Clomipramine enhances prolactin and growth hormone responses to L-tryptophan, Psychopharmacology, 89: 131–133.PubMedCrossRefGoogle Scholar
  2. Anderson, I.M., Cowen, P.J., and Grahame-Smith, D.G., 1988, The effect of BRL 43694 on the neuroendocrine responses to L-tryptophan infusion, J. Psychopharmacol., 2:Abstract.Google Scholar
  3. Anderson, I.M., Crook, W.S., Gartside, S.E., Parry-Billings, M., Newsholme, E.A., and Cowen, P.J., 1989, The effect of moderate weight loss on prolactin secretion in normal female volunteers, Psychiat. Res., 29: 161–167.CrossRefGoogle Scholar
  4. Carlsson, M., Svensson, K., Eriksson, E., and Carlsson, A., 1985, Rat brain serotonin: biochemical and functional evidence for a sex difference, J. Neural Trans., 63: 297–313.CrossRefGoogle Scholar
  5. Charig, E.M., Anderson, I.M., Robinson, J.M., Nutt, D.J., and Cowen, P.J., 1986, L-tryptophan and prolactin release: evidence for interaction between 5-HT1 and 5-HT2 receptors, Human Psychopharmacol., 1: 93–97.CrossRefGoogle Scholar
  6. Charney, D.S., Heninger, G.R., Reinhard, Jr., J.F., Sternberg, D.E., and Hafstead, K.M., 1982, The effect of intravenous L-tryptophan on prolactin and growth hormone and mood in healthy subjects, Psychopharmacology, 77: 217–222.PubMedCrossRefGoogle Scholar
  7. Clemens, J.A., Bennett, D.R., and Fuller, R.W., 1980, The effect of a tryptophan-free diet on prolactin and corticosterone release by serotonergic stimuli, Horm. Metab. Res., 12: 35–38.PubMedCrossRefGoogle Scholar
  8. Cowen, P.J., Gadhui, H., Gosden B., and Kolakowska T., 1985, Responses of prolactin and growth hormone to L-tryptophan infusion: effects in normal subjects and schizophrenic subjects receiving neuroleptics, Psychopharmacology, 86: 164–169.PubMedCrossRefGoogle Scholar
  9. Delgado, P.L., Charney, D.S., Price, L.H., Landis, H., and Heninger, G.R., 1989, Neuroendocrine and behavioral effects of diet tryptophan restriction in healthy subjects, Life Sci., in press.Google Scholar
  10. Eccleston, D., Ashcroft, G.W., Crawford, T.B.B., Stanton, J.B., Wood, D., and McTurk, P.H., 1970, Effect of tryptophan administration on 5-HIAA in cerebrospinal fluid in man, J. Neurol. Neurosurg. Psychiatr., 33: 269–272.PubMedCrossRefGoogle Scholar
  11. Fernstrom, J.D., and Wurtman, R.J., 1971, Brain serotonin content: physiological dependence on plasma tryptophan levels, Science, 173: 149–152.PubMedCrossRefGoogle Scholar
  12. Fernstrom, J.D., and Wurtman, R.J., 1972, Brain serotonin content: physiological regulation by plasma neutral amino acids, Science, 178: 414–416.PubMedCrossRefGoogle Scholar
  13. Fernstrom, J.D., 1988, Tryptophan availability and serotonin synthesis in brain, in: “Amino Acid Availability and Brain Function in Health and Disease”, Huether, G., ed., Springer, Berlin, pp. 137–146.CrossRefGoogle Scholar
  14. Fichter, M.M., Pirke, K.-M., and Holsboer, F., 1984, Weight loss causes neuroendocrine disturbances: experimental study in healthy starving subjects, Psychiat. Res., 17: 61–72.CrossRefGoogle Scholar
  15. Gil-Ad, I., Zambotti, F., Carruba, M.O., Vicentini, I., and Muller, E.E., 1976, Stimulatory role for brain serotonergic system on prolactin secretion in the male rat, Proc. Soc. Exper. Biol. Med., 151: 512–518.Google Scholar
  16. Gillman, P.K., Bartlett, J.R., Bridges, P.K., Hunt, A., Patel, A.J., Kantamaneni, A.J., and Curzon, G., 1981, Indolic substances in plasma, CSF and frontal cortex of human subjects infused with saline or L-tryptophan, J. Neurochem., 37: 410–417.PubMedCrossRefGoogle Scholar
  17. Goodwin, G.M., Fairburn, C.G., and Cowen, P.J., 1987, Dieting changes serotonergic function in women, not men: implications for the aetiology of anorexia nervosa, Psychol. Med., 17: 839–842.PubMedCrossRefGoogle Scholar
  18. Grahame-Smith, D.G., 1971, Studies in vivo on the relationship between brain tryptophan, brain 5-HT synthesis and hyperactivity in rats treated with a monoamine oxidase inhibitor and L-tryptophan, J. Neurochem., 18: 1053–1066.PubMedCrossRefGoogle Scholar
  19. Knott, P.J., and Curzon, G., 1973, Free tryptophan in plasma and brain tryptophan metabolism, Nature, 239: 452–453.CrossRefGoogle Scholar
  20. Lakoski, J.M., and Aghajanian, G.K., 1985, Effects of ketanserin on neuronal responses to serotonin in the prefrontal cortex, lateral geniculate and dorsal raphe nucleus, Neuropharmacology, 24: 265–273.PubMedCrossRefGoogle Scholar
  21. McCance, S.L., Cowen, P.J., Waller, H., and Grahame-Smith, D.G., 1987, The effect of metergoline on endocrine responses to L-tryptophan, J. Psychopharmacol., 1: 90–94.PubMedCrossRefGoogle Scholar
  22. Moir, A.T.B., and Eccleston, D., 1968, The effects of precursor loading on the cerebral metabolism of 5-hydroxyindoles, J. Neurochem., 15: 1093–1108.PubMedCrossRefGoogle Scholar
  23. Mueller, G.P., Twohy, C.P., Chen, H.T., Advis, J.P., and Meites, J., 1976, Effects of L-tryptophan and restraint stress on hypothalamic and brain serotonin turnover, and pituitary TSH and prolactin release in rats, Life Sci., 18: 715–724.PubMedCrossRefGoogle Scholar
  24. Oldendorf, W.H., and Szabo, J., 1976, Amino acid assignment to one of three blood-brain barrier amino acid carriers, Am. J. Physiol., 230: 94–98.PubMedGoogle Scholar
  25. Trulson, M.E., and Jacobs, B.L., 1976, Dose response relationship between systemically administered L-tryptophan or L-5-hydroxytryptophan and raphe unit activity in the rat, Neuropharmacology, 15: 339–344.PubMedCrossRefGoogle Scholar
  26. van Praag, H.M., Asnis, G., and Zukin, S., 1986, Peripheral hormones: a window on the central MA? Psychopharmacol. Bull., 22: 565–570.PubMedGoogle Scholar
  27. Young, S.N., and Gauthier, S., 1981, Effect of tryptophan administration on tryptophan, hydroxyindo1eacetic acid and indoleacetic acid in human lumbar and cisternal cerebrospinal fluid, J. Neurol. Neurosurg. Psychiat., 44: 323–328.PubMedCrossRefGoogle Scholar
  28. Young, S.N., Gauthier, S., Anderson, G.M., and Purdy, W.C., 1980, Tryptophan, 5-hydroxyindoleacetic acid and indoleacetic acid in human cerebrospinal fluid: interrelationships and the influence of age, sex, epilepsy and anticonvulsant drugs, J. Neurol. Neurosurg. Psychiat., 43: 438–445.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1991

Authors and Affiliations

  • I. Anderson
    • 1
  • P. Cowen
    • 1
  1. 1.MRC Clinical Pharmacology Unit and University Department of Psychiatry Research UnitLittlemore HospitalOxfordUK

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