The effect of aspirin on the fibrinolytic activity of gastric juice.

Fibrinolytic activity in the gastric juice of normal subjects has been studied by a double-blind cross-over technique comparing the effect of placebo and pentagastrin against aspirin and pentagastrin. Aspirin effectively produced a gastritis and pure fibrinolytic activity was detected in the gastric juice, but the number of samples showing pure fibrinolytic activity did not differ between the two groups. In both the placebo and the aspirin groups the presence of a protease active at neutral pH and capable of dissolving fibrin is confirmed. Aspirin is unlikely to cause gastric bleeding by increasing local fibrinolytic activity within the stomach. The model, so constructed, is not sensitive enough to be of value in investigating further the role of gastric fibrinolytic activity in gastric haemorrhage.