[Erythrocyte membrane transport of amino acid precursors of monoamines in schizophrenic patients. Comparison with depressive patients].

The study concerned 72 schizophrenic and 200 depressed patients hospitalised between 1983 and 1990. The erythrocyte membrane transports (EMT) of L-tyrosine and L-tryptophan (at 37 degrees, 0 degrees and 37-0 degrees) of schizophrenics without treatment nor depression were different compared to controls and depressed patients. The schizophrenics under neuroleptic treatment and/or depressed showed same means of EMT values as depressed patients. The slopes of the correlations between EMT of tyrosine or tryptophan at 37 degrees, 0 degrees and 37-0 degrees, as well as that between plasma levels of these amino acids, were parallel. However the slopes of the correlations between EMT of tyrosine and tryptophan were different according to the subgroups of patients: the perturbations of EMT were related to the clinical characteristics. In depressed patients and in schizophrenic patients under neuroleptic treatment and/or depressed, little changes in EMT of tyrosine were related to high changes of EMT of tryptophan.