Fluid pressure and fibrinolytic activity in implanted subcutaneous and intramuscular capsules

Using the capsule implantation method, the relationship between the intracapsular fluid pressure (IFP) and fibrinolytic activity of the intracapsular fluid was examined in subcutaneous and intramuscular capsules. When IFP was positive, the sterility test was positive (indicating infection), the fibrinolytic activity was enhanced, and the response of IFP to volume change or hypertonic solutions was poor. On the other hand, when IFP was negative, the sterility test was negative, the fibrinolytic activity was weak, and the response of IFP to volume change or hypertonic solutions was good. Also, the more negative the IFP, the weaker was the fibrinolytic activity in the intracapsular fluid (r = 0.60, p less than 0.01). The ratio of the intracapsular fluid fibrinolytic activity to the plasma fibrinolytic activity showed a good correlation to the intracapsular fluid pressure (r = 0.68, p less than 0.01). When the fibrinolytic activity was activated by injection of streptokinase and human plasma, the IFP showed a tendency to increase. These results suggest that the fibrinolytic system plays some role in the maintenance of local fluid balance.