Neuroendocrine Responses to Tryptophan as an Index of Brain Serotonin Function
Published 1 January 1988
Philip J. Cowen
Citations5
Generate an AI Snapshot to get a quick, structured summary of this paper.
Study Snapshot
ObjectiveStudy objective
MethodsResearch methodology
PopulationPopulation studied
Sample sizeSample sizes
OutcomesStudy outcomes here
ResultsStudy results comes here
LimitationsResearch study limitations comes here
A concise AI-generated summary of the paper will appear here once you click Generate AI Snapshot.
TL;DR
The present chapter reviews the evidence that this neuroendocrine response is mediated by increases in brain 5-HT function and also examines whether abnormal PRL responses to LTP are seen in depressed patients.
Abstract
Drugs that increase brain serotonin (5-hydroxytryptamine, 5-HT) function elevate plasma levels of certain anterior pituitary hormones, notably prolactin (PRL), ACTH and growth hormone (GH) (1). Administration to humans of the serotonin precursor L-tryptophan (LTP), reliably elevates plasma PRL concentration (1). The present chapter reviews the evidence that this neuroendocrine response is mediated by increases in brain 5-HT function and also examines whether abnormal PRL responses to LTP are seen in depressed patients.
Keywords
MedicineNeuroscience
Archives of General PsychiatrySerotonergic Function in Depression
278 Citations1984George R. Heninger
There was a marked blunting of the maximal prolactin response to the tryptophan in both the male and female patients, providing strong support for a possible serotonergic abnormality in depression.
Life SciencesPlasma prolactin changes following fenfluramine in depressed patients compared to controls: An evaluation of central serotonergic responsibility in depression
237 Citations1984Larry J. Siever, Dennis L. Murphy +3 more
The results suggest that the central serotonergic system is less responsive in depressed patients than controls, and fenfluramine, a serotonin releasing agent, was administered to 18 depressed patients and 10 controls.
Psychological MedicineNeuroendocrine tests of monoamine function in man: a review of basic theory and its application to the study of depressive illness
225 Citations1980Stuart Checkley
The results of these studies support the hypothesis that there is defective noradrenergic function in the brains of some patients with depressive illness.
Archives of General PsychiatryEffect of 5-Hydroxytryptophan on Serum Cortisol Levels in Major Affective Disorders
199 Citations1984Herbert Y. Meltzer
The results suggest increased 5-HT receptor sensitivity may be present, possibly in the hypothalamus or pituitary, in some patients with affective disorders.
Archives of General PsychiatryNeuroendocrine Responses to Intravenous Tryptophan in Major Depression
129 Citations1987Philip J. Cowen
Depressed patients have different types of abnormal 5-hydroxytryptamine-mediated neuroendocrine responses that correlate with the presence or absence of severe weight loss and cortisol hypersecretion, and these abnormalities are central to the depressive disorder or have implications for treatment response.
Archives of General PsychiatryEffect of 5-Hydroxytryptophan on Serum Cortisol Levels in Major Affective Disorders
118 Citations1984Herbert Y. Meltzer
Serum cortisol levels were significantly higher after administration of 5-hydroxytryptophan (5-HTP), 200 mg orally, in unmedicated patients with affective disorders than in controls and tended to correlate with the SADS-C manic syndrome score.
Psychological MedicineDieting changes serotonergic function in women, not men: implications for the aetiology of anorexia nervosa?
98 Citations1987Guy M. Goodwin, Christopher G. Fairburn +1 more
It is suggested that dieting alters brain 5–HT function in women but not in men, and biological factors as well as greater psychosocial pressures to diet may contribute to the high prevalence of eating disorders amongst women.
PsychopharmacologyResponses of prolactin and growth hormone to L-tryptophan infusion: Effects in normal subjects and schizophrenic patients receiving neuroleptics
74 Citations1985Philip J. Cowen, HARISH GADHVI +2 more
Intravenous infusion of l-tryptophan in 18 normal subjects produced a significant increase in plasma prolactin, growth hormone, and self-ratings of drowsiness, and Schizophrenic patients receiving neuroleptics had increased PRL response to LTP, possibly because of the drug-induced disinhibition of PRL release.
Psychological MedicineDiazepam alters brain 5-HT function in man: implications for the acute and chronic effects of benzodiazepines
49 Citations1987David Nutt, Philip J. Cowen
It is possible that excessive ‘rebound’ 5-HT activity may contribute to the abstinence syndrome seen on benzodiazepine withdrawal, and a reduction in brain 5- HT function may underlie some of the acute therapeutic actions of Benzodiazepines.
Trends in Pharmacological SciencesPsychotropic drugs and human 5-HT neuroendocrinology
35 Citations1987Philip J. Cowen
The value of 5- HT neuroendocrine tests for assessing the potential clinical effects of novel ligands for 5-HT receptors as well as helping to elucidate the actions of conventional psychotropic agents is examined.
Journal of PsychopharmacologyThe effect of metergoline on endocrine responses to L-tryptophan
22 Citations1987S McCance, Philip J. Cowen +2 more
Results are consistent with the proposal that the prolactin response to L-tryptophan is mediated by 5-HT1 receptors; however, metergoline might also reduce prolactIn responses by a dopaminergic action.
Psychiatry and Clinical NeurosciencesGrowth Hormone Responses to Administration of L‐5‐Hydroxytryptophan (L‐5‐HTP) in Manic‐Depressive Psychoses
21 Citations1973Saburo Takahashi, Hisao Kondo +3 more
Fourteen hospitalized patients with manic‐depressive psychoses received L‐5‐hydroxy‐tryptophan (L‐ 5‐HTP), a serotonin precursor, which has been postulated as a potent antidepressive agent.