Endogenous levels of free and conjugated urinary 3-methoxy-4-hydroxyphenylethyleneglycol in control subjects and patients with pheochromocytoma determined by reversed-phase liquid chromatography with electrochemical detection.
A sensitive and specific reversed-phase liquid-chromatography (HPLC) method for the determination of urinary free and conjugated 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) was developed. Sample preparation is minimal and the method is ideally suited for routine clinical assays of this catecholamine metabolite. Reported in this paper are excretion profiles of controls subjects and patients with pheochromocytoma. Quantitative results were expressed as microgram MHPG per mg creatinine, in order to eliminate variations associated with the 24-h urine collection. The levels of free and conjugated MHPG, determined in 20 control subjects ranged between 0.04--0.11 microgram/mg of creatinine and 0.48--1.25 microgram/mg of creatinine, respectively. The corresponding levels of free and conjugated MHPG in 8 patients with pheochromocytoma were 0.29--1.21 microgram/mg of creatinine and 2.47--15.98 microgram/mg of creatinine, respectively. The described liquid-chromatographic analysis, coupled with the highly sensitive electrochemical detection, provides a simple and reliable method for metabolic profiling of catecholamine by-products at their endogenous levels. This offers an attractive possibility for the detection of neural crest lesions which may cause problems in diagnosis because of their small size, infrequent occurrence and symptoms similar to those of essential hypertension.
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006018:Glycols / Q000652:urine*; D006801:Humans; D008734:Methoxyhydroxyphenylglycol / Q000652:urine*; D010673:Pheochromocytoma / Q000652:urine*
D006018:Glycols; D008734:Methoxyhydroxyphenylglycol