Free and total 3-methoxy-4-hydroxyphenylethylene glycol in human cerebrospinal fluid: relationship to blood pressure in hypertensives and patients with neuropsychiatric disease.

The concentrations of free and total 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) in the cerebrospinal fluid of 43 patients were measured by selected ion monitoring gas chromatography-mass spectrometry using MHPG specifically labelled with deuterium as internal standard. Unpaired Wilcoxon comparisons of free and total MHPG concentrations in males and females showed no significant difference between the sexes. The relationships between free, conjugated and total MHPG concentrations and age, blood pressure, glucose and protein levels in cerebrospinal fluid were examined by linear regression analysis. The only significant correlations found were between free MHPG and glucose and between total MHPG and glucose.