The determination of bufotenin in urine of schizophrenic patients and normal controls

Abstract

One-dimensional chromatography, quantification without previous qualitative identification and without adequate separation of the tertiary amine fraction have all contributed to the confusion in regard to the identification and quantification of bufotenin. We have used for the positive identification of bufotenin: (1) DACA; (2) diazotized o-tolidine, and (3) OPT. Of the three, the last was found to be the most sensitive and specific since it combines in one test the qualitative identification, separation by two-dimensional TLC and the quantitative estimation—all in one step. In our opinion in view of the high sensitivity of this method it should prove a useful screening tool for the identification and quantification of bufotenin in urine samples collected over an 8-hr period. In our experience with urine samples of normals, in contrast to those of chronic schizophrenics and acute schizophrenics, no bufotenin was found in the urine of any normals even when the normals were on an MAO inhibitor and L-cysteine loading. When bufotenin was identified in chronic schizophrenics, the levels were found to be between 3 and 5 μg in 24-hr urine samples. On these standards the negative results found in normals are rated as zero. In the methods we have adopted for the identification of bufotenin, the extraction and separation techniques for N,N-dimethylated compounds—two-dimensional TLC, multiple spray reagents (DACA, diazotized o-tolidine, OPT) and spectrofluorometry when the fluorescence of the OPT products is specific for 5-hydroxytryptaminic compounds— render the identification more conclusive than that by earlier methods. Supportive evidence has been provided by GLC of the amine fractions and their trimethylsilyl derivatives. Work on identification by gas chromatography-mass spectrometry is now in progress. Fisher and Spatz 5 and Sireix and Marini 15 reported fairly high levels of bufotenin even in the urine of normal subjects. If this were the case, the more sensitive OPT method should have given positive results in all urine samples from normals.