Determination of catecholamines and their 3‐O‐methyl metabolites in mouse plasma

Abstract

The determination of catecholamines and their 3-O-methyl metabolites in a single mouse plasma is necessary to understand the role of the sympathetic nervous activity, while the inactivation of catecholamines by catechol-O-methyltransferase indicates the activity of blood pressure regulation in animals. Here we report the basal catecholamines and their 3-O-methyl metabolite concentrations obtained from 15 µL of mouse plasma utilizing semi-microcolumn high-performance liquid chromatography (HPLC)-peroxyoxalate chemiluminescence detection system. The concentrations were 6.63 ± 1.37 pmol/mL plasma, 0.49 ± 0.10 pmol/mL plasma, 5.25 ± 2.30 pmol/mL plasma, 3.23 ± 0.84 pmol/mL plasma, 0.44 ± 0.11 pmol/mL plasma, and 3.39 ± 1.67 pmol/mL plasma for norepinephrine, epinephrine, dopamine, normetanephrine, metanephrine and 3-methoxytyramine, respectively (n = 5–7). Further, when blood pressure was reduced by minoxidil, plasma catecholamines were found to be significantly increased by the baroreflex-mediated response in mouse. Copyright © 2001 John Wiley & Sons, Ltd. Abbreviations used: CA catecholamine COMT catehol-O-methyltransferase DA dopamine E epinephrine MN metarephrines 3-MT, 3-methoxytyramine NE norepinephrine NMN normetanephrine SHR spontaneously hypertensive rats. WKR Wystar Kyoto rats.