Plasma and urinary catecholamines and metabolites during physical exercise in essential hypertension

The effect of physical exercise on plasma catecholamines and urinary catecholamines and metabolites was studied in 11 patients with established essential hypertension, 5 patients with borderline hypertension, and 9 healthy volunteers. Resting plasma noradrenaline and the changes following exercise were similar in all the investigated groups. Although the resting urinary noradrenaline excretion was similar in patients and in controls, an exaggerated increase of noradrenaline excretion occurred in hypertensive patients during physical work. This finding suggests sympathetic overreactivity in essential hypertension. The increased plasma levels of adrenaline, found in established hypertension, were associated with its diminished urinary clearance. These results imply altered renal handling of adrenaline in essential hypertension. Physical exercise was associated with enhancement of metabolism of noradrenaline to 3-methoxy,4-hydroxy-phenylglycol in all groups of subjects, but the stimulation of this pathway was particularly pronounced in healthy subjects. In essential hypertension, the pattern of urinary excretion of catecholamines and metabolites suggests impaired noradrenaline metabolism during exercise. The only characteristic feature of borderline, as opposed to established hypertension, was the increased urinary excretion of dopamine.