This study is desinged to investigate exercise-induced change of coagulation and fibrinolysis systems. The plasma levels of both the fibrinolytic factors including tissue type plasminogen activator (t-PA) antigen urokinase-type plasminogen activator (u-PA) antigen, plasminogen activator (PA) activity and plasmin-α2 plasmin inhibitor (plm-α2PI) complex, and the coagulation factors including factor VIII related antigen (VIII R: Ag), factor VIII activity (VIII: C) and protein C (PC) antigen were measured before exercise and immediately, 15min, 30 min and 60min after exercise on treadmill. The levels of VIII R: Ag and VIII: C rose slightly after exercise, but PC antigen did not change. The levels of t-PA antigen, PA activity and plm-α2 PI complex elevated immediately after exercise and then decreased gradually. The levels of both t-PA antigen and PA activity returned to the control levels 60min after exercise. In contrast, the level of u-PA antigen was not affected by exercise. These data suggest that the exercise-induced elevation of plasma PA activity may be caused by t-PA but not by u-PA.
The degree of elevation of t-PA and PA activity in the plasma after exercise was lower in old aged group as comparied with that in young aged group.
