ELECTRIC-FOOT-SHOCK INDUCED THE SUPPRESSION OF FIBRINOLYTIC-ACTIVITY IN RATS

Electric-foot-shock was given to rats to initiate constant mental stre ss and its effect on fibrinolytic activity was analyzed. After the ter mination of electric-foot-shock which was given for an hour, euglobuli n clot lysis time in the stressed group significantly prolonged than t hose in the control group. Tissue plasminogen activator activity was a lso significantly lower in the stressed group. These effects lasted at least for an hour and returned to the control values 24 hours after t he stress. Whole blood serotonin levels, which mainly show serotonin c ontents in platelets, were higher in the stressed group. A negative co rrelation between whole blood serotonin and tPA activity in the stress ed group was obtained. These results suggest that prolonged mental str ess impairs fibrinolysis by decreasing tPA activity with a concomitant increase of serotonin contents in platelets.