Effect of orthostatic changes on urokinase excretion

The effects of orthostatic changes on the excretion of urokinase were studied in healthy normal volunteers. Urokinase excretion rose (average +69%) significantly (p less than .005) while urine volume fell (average-59%) significantly (p less than .001) after the subjects had been standing. There was no difference between men and women nor was there an apparent diurnal variation in urokinase excretion of recumbent subjects. A relationship between urokinase excretion and sympathetic nervous system activity is suggested.