The excretion of free noradrenaline and adrenaline by healthy young subjects and by patients with essential hypertension.

Abstract

SUMMARYThe possible relationship between arterial pressure and the excretion of free noradrenaline and adrenaline in the urine was the subject of a study of 58 university students and 33 patients with untreated essential hypertension. The urine was collected during the morning with the subjects fasting, recumbent and undisturbed.The mean excretion rate of free noradrenaline by the students was 0.94 µg. per hour and by the hypertensives, 1.65 µg. per hour. The mean excretion rates of free adrenaline were 0.47 and 0.73 µg. per hour respectively. Although the difference in catecholamine excretion rates between the two groups was highly significant (P = < 0.01), there was a considerable overlap.There was a significant correlation with the student group between the excretion of both free noradrenaline and adrenaline and the systolic blood pressure, demonstrating that, in normal subjects, casual blood pressure at rest is partly although not very closely related to catecholamine production. Although catecholamine excretion rates were higher in the hypertensive group, a significant correlation with blood pressure was not found.