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Comparison of plasma 3,4‐dihydroxyphenylethylene glycol (DHPG) and norepinephrine levels as indices of sympathetic activity in man
Author(s) -
HOWES L. G.,
HAWKSBY CATHERINE C.,
REID J. L.
Publication year - 1986
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1986.tb01301.x
Subject(s) - norepinephrine , supine position , medicine , chemistry , endocrinology , sympathetic nervous system , catecholamine , sympathetic activity , heart rate , epinephrine , blood pressure , anesthesia , dopamine
. Plasma levels of norepinephrine (NE) and the NE metabolite 3,4‐dihydroxyphenylethylene glycol (DHPG) were measured simultaneously following sympathetic activation induced by standing, cold pressor testing and bicycle exercise at progressively increasing workloads in normal volunteers. Free DHPG and NE levels both increased with sympathetic activation, but free NE levels were a more sensitive index of change. In addition, plasma free NE levels more closely reflected the fall in heart rate following exercise than free DHPG. In contrast to free levels, conjugated DHPG and NE levels did not change significantly after exercise. Supine resting free DHPG/ NE ratios were always greater than 2·0, but fell progressively with increasing sympathetic activation because of a proportionately greater rise in NE than DHPG. The simultaneous measurement of plasma free DHPG and NE does not offer advantages over free NE levels as an index of sympathetic activity in man, but may be of use in the diagnosis of pheochromocytoma and in studies of NE metabolism.