TISSUE-TYPE PLASMINOGEN-ACTIVATOR AND PLASMINOGEN-ACTIVATOR INHIBITOR-1 AFTER EXERCISE - COMPARISON TO VENOUS OCCLUSION AND DDAVP

Nineteen healthy young men were subjected randomly to maximal exercise on treadmill, venous occlusion (VO) and infusion of DDAVP on three different mornings. Alter exercise t-PA antigen increased by 2.8 fold, after VO by 5.1 fold and after DDAVP by 2.4 fold (all P<0.01). PAI-1 antigen did not change significantly after any of the stimuli. Therefore, increases in t-PA activity and decreases in PAI-1 activity observed after stimulation were attributed to released t-PA antigen only: increase in t-PA activity after exercise was 2.2 fold lower than that after VO and 1.8 fold higher than after DDAVP. No PAI-1 activity could be detected in 81 9 samples after exercise, in 15 19 samples after VO and in 5/19 after DDAVP. Positive correlations were observed for t-PA antigen release between the three stimuli (VO-DDAVP: r=0.78, P<0.01; exercise-DDAVP: r=0.53, P<0.05; VO-exercise: r=0.30, not significant). It was concluded that maximal exercise as a stimulus of t-PA release is less effective than VO and similar to DDAVP. Divergent alterations of t-PA and PAI-1 antigens after stimulation argue against a common regulation of their acute release from tissue stores. © 1990.