INCREASED URINARY EXCRETION OF CATECHOL AMINES IN THE ABSENCE OF KNOWN CHROMAFFIN TUMORS

Abstract

The urinary excretion of biologically active catechol amines was surveyed in 802 unselected, hospitalized patients. The rabbit aortic-strip method was used for assay. Normal values determined in 10 healthy, ambulatory medical students were 1.9 to 10.8 [mu]g. (net) of norepinephrine equivalents per hour. Thirty-seven of the 802 patients excreted 12 [mu]g. or more (net) of norepinephrine equivalents per hour in the urine and 2 of the 37 excreted as much as 72 [mu]g. per hour. Increased excretion was more consistently observed in patients who had liver disease, infection of some type, a psychosis, or who died during the period of observation. Many of the patients had more than one illness, and various combinations of the foregoing factors were common in the patients with increased excretion. Possible explanations for these observations are briefly discussed. It is concluded that the isolated finding of "increased" excretion of catechol amines by the method herein employed probably should not be accepted as prima facie evidence of a pheochromocytoma. From a practical standpoint, this should not detract from using the test as a screening procedure for pheochromocytoma, provided the entire clinical situation is taken into account when interpreting the results.