Analysis of the O-methylated metabolites of isoprenaline, adrenaline and noradrenaline in physiological salt solutions by high-performance liquid chromatography with electrochemical detection.

This study provides the first report of a sensitive, simple and rapid high-performance liquid chromatographic (HPLC) assay for the simultaneous analysis of isoprenaline and its metabolite, 3-O-methylisoprenaline, in samples of physiological salt solutions. The assay does not require time-consuming sample clean-up or extraction procedures and uses a Nova-Pak C18 column, an isocratic mobile phase and an amperometric detector. In addition, small modifications to the composition of the mobile phase have also provided sensitive assays for noradrenaline and adrenaline and their O-methylated or O-methylated deaminated metabolites (normetanephrine, metanephrine, 3-methoxy-4-hydroxyphenylethylene glycol and 3-methoxy-4-hydroxymandelic acid). These HPLC assays are sufficiently sensitive and rapid to replace the use of [3H]amines and column chromatographic separation of the metabolites for most in vitro studies on the uptake and subsequent metabolism of catecholamines by monoamine oxidase and/or catechol-O-methyltransferase in tissues.