Plasma Norepinephrine and Dihydroxyphenylglycol in Essential Hypertension

The aim of the present study was to examine whether essential hypertension is associated with altered plasma concentrations of dihydroxyphenylglycol, the principal presynaptic metabolite of norepinephrine. Forearm venous plasma dihydroxyphenylglycol and norepinephrine were determined at rest and during graded orthostasis in 47 normotensive control subjects and 58 outpatients with essential hypertension. There was no group difference in age. At supine rest as well as during sitting and standing, hypertensive subjects had plasma norepinephrine concentrations similar to those in normotensive control subjects, but plasma dihydroxyphenylglycol concentrations were higher than those in normotensive control subjects. Both groups snowed a linear relation between plasma dihydroxyphenylglycol (ordinate) and plasma norepinephrine (abscissa). The resulting regression line was steeper (p