title: Determination of 4-O-methylated catecholamine metabolites in urine by mass fragmentography.
abstract: We describe the determination of the 4-O-methylated catecholamine metabolites 4-methoxy-3-hydroxyphenylacetic acid (iso-HVA), 4-methoxy-3-hydroxyphenylmandelic acid (iso-VMA) and 4-methoxy-3-hydroxyphenylethylene glycol (iso-MOPEG) in urine with use of mass fragmentography and deuterated internal standards. Normal values, expressed in terms of creatinine, are given as a function of age. Urinary excretion values during neuroblastoma, pheochromocytoma, and parkinsonism treated with L-DOPA, and during the intravenous administration of dopamine are discussed. For normal persons, the mean percentages (+/- SD) of 4-O-methylated metabolites relative to their 3-O-methylated analogs were 6.29 +/- 2.79% (iso-HVA/HVA), 0.70 +/- 0.57% (iso-VMA/VMA), and 0.77 +/- 0.53% (iso-MOPEG/MOPEG). We observed no significant changes in these parameters for the patients studied and conclude that the determination of 4-O-methylated catecholamine metabolites for these patients does not add information to the results obtained from their quantitatively more important 3-O-methylated analogs.
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006018:Glycols / Q000652:urine*; D006719:Homovanillic Acid / Q000031:analogs & derivatives / Q000652:urine*; D006801:Humans; D007536:Isomerism; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000652:urine*; D010648:Phenylacetates / Q000652:urine*; D013329:Structure-Activity Relationship; D014642:Vanilmandelic Acid / Q000031:analogs & derivatives / Q000652:urine*
chemical_list: D006018:Glycols; D010648:Phenylacetates; C021208:isohomovanillic acid; C021209:isoMHPG; D008734:Methoxyhydroxyphenylglycol; D014642:Vanilmandelic Acid; C021210:isovanilmandelic acid; D006719:Homovanillic Acid