ORAL administration of a large amount of methionine to schizophrenic patients who had been treated with a monoamine oxidase inhibitor (MAOI) was reported to produce psychic symptoms which have been interpreted either as an intensification of schizophrenic symptoms or as superimposed toxic symptoms1–4. The effects of methionine and MAOI have been explained as an increase in the amounts of methylated amines, such as bufotenin, N,N-dimethyltryptamine, 3,4-dimethoxyphenylethylamine or unknown amines which have been claimed to be psychotogenic substances. One of the purposes of the present experiments is to determine whether methionine increases the rates of N or O-methylation of catechol and indolic amines.
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KAKIMOTO, Y., SANO, I., KANAZAWA, A. et al. Metabolic Effects of Methionine in Schizophrenic Patients pretreated with a Monoamine Oxidase Inhibitor. Nature 216, 1110–1111 (1967). https://doi.org/10.1038/2161110a0
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