3-Methoxy-4-hydroxyphenylglycol in human cerebrospinal fluid

3-Methoxy-4-hydroxyphenylglycol (MHPG) free and sulphate conjugate concentrations were investigated in human lumbar cerebrospinal fluid from a group of 48 subjects of both sexes, using a sensitive and direct reversed-phase liquid chromatographic method with amperometric detection, improved with the adoption of 4-methoxy-3-hydroxyphenylglycol (iso-MHPG) as internal standard. The mean value of free MHPG was 7.30 ± 1.90 μg/1 (SD) and 8.10 ± 2.8 μl/1 in males (28) and females (20) respectively, and the MHPG sulphate conjugate represented about 5% of free metabolite in both sexes. In addition, the correlations between MHPG levels and patients' age and sex were also discussed, as were criteria for subject selection.