IDENTIFICATION AND QUANTIFICATION OF 3-METHOXY -4-HYDROXYPHENYLLACTIC ACID (VLA) IN CEREBROSPINAL FLUID AND 3-METHOXY-4-HYDROXY PHENYLPYRUVIC ACID (VPA) IN THE URINE OF PARKINSONIAN PATIENTS TREATED WITH L-DOPA

The identification and quantification of 3-methoxy-4-hydroxyphenyllactic acid in cerebrospinal fluid, and 3-methoxy-4-hydroxyphenylpyruvic acid in the urine of Parkinsonian patients on medication with l-3,4-dihydroxyphenylalanine with or without a peripheral decarboxylase inhibitor are described. Data are also given for other catecholamine- and catecholamine precursor metabolites in urine and cerebrospinal fluid. Analyses were performed by means of gas chromatography with flame ionization or mass spectrometric detection. We have concluded that following the administration of l-3.4-dihydroxyphenylalanine + peripheral decarboxylase inhibitor. 3-methoxy-4-hydroxyphenyllactic acid must be considered as a quantitatively important metabolite of L-3.4-dihydroxyphenylalanine in cerebrospinal fluid. In addition, some comment is given on the presence of 3-methoxy-4-hydroxy-phenylpyruvic acid in the urine of these patients.