Effect of sampling site and conditions on plasma levels of noradrenaline, adrenaline and dopamine.
Levels of noradrenaline, adrenaline and dopamine were measured simultaneously from different sites, during stimulation and during noradrenaline infusion. Levels of the three catecholamines were similar in low inferior vena cava and a forearm vein. The ratio between adrenal venous and peripheral levels averaged 49:1 for adrenaline but only 4:1 for noradrenaline, consistent with other significant sources for noradrenaline apart from the adrenal. Levels of dopamine were only slightly higher in adrenal venous blood, consistent with the adrenal being a minor source in these subjects. Forearm arteriovenous differences for adrenaline and noradrenaline demonstrated significant removal of these amines across this vascular bed. To monitor sympathetic responses, venous noradrenaline appears satisfactory, but venous adrenaline would miss responses detected by arterial levels. Sympathetic responses were not reflected by changes in either arterial or venous dopamine.
D001158:Arteries; D001794:Blood Pressure; D004298:Dopamine / Q000097:blood*; D004837:Epinephrine / Q000097:blood*; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000097:blood*; D009638:Norepinephrine / Q000097:blood*; D009928:Organ Specificity; D011187:Posture; D014680:Veins
D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine