Anti-coagulant and anti-thrombotic effects of some protease inhibitors.

Several synthetic tri-peptide enzyme inhibitors of the general sequence Phe-Pro-Arg were studied in vitro and in vivo. Extent and specificity of inhibition of thrombin were different. The inhibitors exert anti-coagulant effects in vitro. The anti-coagulant effect in vivo was used as a measure of bioavailability and duration of action. The tri-peptide inhibitors are rapidly eliminated from the circulation and produce a decrease in blood pressure. Anti-thrombotic effects were demonstrated in a thrombosis model in rabbits.