The Daily Rhythm of Plasma Tryptophan and Tyrosine in Depression

The erythrocyte membrane transport (MT) of L-tyrosine (TYR) and L-tryptophan (TRP) and their plasma concentration showed abnormal mean values in 37 depressed patients compared to control subjects before treatment. The pattern of these abnormal values differed according to the clinical subgroup (DSM III criteria). In bipolar disorders the TYR values were all low and the TRP values showed little change, except a low level of plasma TRP. In major depressions, MT were abnormal (MT TYR low, MT TRP high) with a very low plasma TRP. In dysthymic disorders the TYR and TRP values were normal. The normalization of the above biochemical variables was significantly correlated with the clinical improvement; however, the plasma concentration of TRP remained abnormal in some patients who had recovered. In contrast, only plasma TYR and TRP were significantly increased in patients without recovery.

Section: Discussionsupporting

confidence: 90%

Evolution of Red Blood Cell Membrane Transport and Plasma Level of L-Tyrosine and L-Tryptophan in Depressed Treated Patients According to Clinical Improvement

Bovier¹,

Widmer²,

Gaillard³

et al. 1988

“…Further, clinical improve ment correlates with normalization of these biochemical parameters [Bovier et al, 1988], Plasma red cell trans ports of tyrosine and tryptophan were then hypothesized to be valuable biological markers in affective disorders: abnormalities in the function of brain neurotransmitters could be implicated in their etiology. It must also be acknowledged that many previous investigations con cerning plasma levels of different amino acids in the field of depression have until now yielded inconsistent findings [Niskanen et al, 1976;De Myer et al. 1981;Möller et al, 1985;Maes et al, 1987], However, this question should be carefully formulated in a context of complexity each parameter 'per se' gets intrinsic proper ties but is also integrated in a functional system which confers on its 'elementary' properties.…”

Section: Introductionmentioning

confidence: 99%

A Multivariate Analysis of Red Blood Cell Membrane Transports and Plasma Levels of L-Tyrosine and L-Tryptophan in Depressed Patients before Treatment and after Clinical Improvement

Chiaroni

Azorin²,

Bovier

et al. 1990

The purpose of this study was to examine whether biological variables, such as erythrocyte membrane transports and plasma levels of monoamine precursor amino acids (tyrosine, tryptophan and phenylalanine), exhibit a particular pattern relatively to DSM-III depressive subgroups (dysthymic disorders, major recurrent depression and biopolar depression), when they are treated synthetically by a stepwise discriminant analysis. We conducted two tests in 97 subjects (64 depressed patients vs. 33 controls): the first before any antidepressant treatment, and the second after pharmacotherapy and clinical improvement. Our results clearly indicate a satisfying homogeneity for the controls and bipolar depressed patients as opposed to dysthymic disorders and major recurrent depression in both tests. The most informative biological variables are the erythrocyte membrane transports before treatment, tryptophan parameters after clinical improvement. Evidence is provided that multivariate analysis constitutes an interesting approach in biological psychiatry.

“…Des perturbations de la capture des acides aminés ont été rattachées à divers déficits membranaires comportant no tamment un mauvais fonctionnement du système (Na+K+)ATPase, ou des anomalies dans les mouvements des électrolytes, du Na+ en particulier [Mendels et Frazer, 1974;Hokin-Neaverson et al, 1975;Ramsey et al, 1979], Des taux endogènes de TYR supérieurs à la normale ont été observés chez les mania ques [Moody et al, 1977;Möller et Amdisen, 1979], alors que l'on note une modification des rythmes journaliers chez les dépressifs [Niskanen et al, 1976], Tissot et al [1978], Gaillard et Tissot [1979] ont mesuré les diffé rences artérioveineuses cérébrales chez plu sieurs maniaco-dépressifs après une sur charge de L-Dopa, connue pour être captée de la même manière que la TYR [Lajtha, 1968], Dans ce cas, ils observent une faible capture cérébrale de TRY en corrélation avec un important efflux de TYR chez les dépres sifs, l'inverse se produisant chez les mania ques. Les échanges ont lieu entre le plasma et d'autres compartiments parmi lesquels les cellules sanguines, les érythrocytes en parti culier, doivent être considérées.…”

Section: Introductionunclassified

Mécanisme d’échange de la tyrosine entre le plasma et les érythrocytes chez le sujet normal et des patients psychiatriques

Widmer¹,

Gaillard²,

Dick³

et al. 1982

The saturable mechanism of tyrosine (TYR) uptake by the membrane of red blood cells incubated at 37 °C has been studied in normal subjects and psychiatric patients. This uptake is markedly inhibited by incubation at 0 °C, and weakly inhibited by iodoacetic acid and ouabain. The uptake of TYR is significantly lower in unipolar- and bipolar-depressed patients, and significantly higher in schizophrenics compared to normal controls. These results indicate a possible disturbance of functional capacity of membrane transport in some psychiatric diseases.