[Simultaneous liquid chromatographic determination of plasma 3,4-dihydroxyphenylglycol and norepinephrine as indicators of sympathetic activity].

A high performance liquid chromatographic method with electrochemical detection is described for simultaneously measuring the concentrations of the endogenous catecholamines and the deaminated catecholamine metabolite 3,4-dihydroxyphenyglycol (DHPG) in plasma. Plasma DHPG concentrations as determined by the present method were 734 +/- 77pg/ml after 30 min. of supine rest whereas plasma norepinephrine (NE) concentrations were 114 +/- 20pg/ml in 5 healthy subjects. The DHPG and NE concentrations increased to 891 +/- 64 and 266 +/- 36pg/ml, respectively, after 30 min. of upright position following 30 min. of supine rest. The simultaneous measurement of plasma DHPG and NE concentrations may provide a more comprehensive assessment of the sympathetic nervous system.