(AQUEOUS SOLUTION OF HAEMOCOAGULOSE ISOLATED FROM VENOM OF BOTHROPS JARARACA OR BOTHROPS ATROX,CONTAINING 0.9% OF SOD CHLORIDE). BOTROPASE ACT ON FIBRINOGEN TO PRODUCE A FIBRIN MONOMER THAT CAN BE CONVERTED BY THROMBIN TO A FIBRIN CLOT. THE ACTION OF BOTROPASE IN THIS WAY IS SIMILAR TO THAT OF THROMBIN, WHICH CONVERTS FIBRINOGEN INTO FIBRIN WITHOUT THE INTERVENTION OF ANY OTHER FACTORS. THERE ARE HOWEVER, SOME SIGNIFICANT DIVERGENCES BETWEEN THE MODE OF ACTION OF BOTROPASE AND THAT OF THROMBIN, THE PRINCIPAL ONES BEING THE FOLLOWING. 1. THE ACTION OF THROMBIN MAY BE INHIBITED BY THE ANTITHROMBIN NORMALLY EXISTING IN THE BLOOD, WHEREAS THE ACTION OF BOTROPASE CONTINUES, EVEN WHEN ANTITHROMBJP IS PRESENT.
2. BY THE ACTION OF EITHER THROMBIN OR BOTROPASE, THE TERMINAL AMINOACIDS IN THE FIBRIN CLOTS CONSIST OF TYROSINE AND GLYCINE; HOWEVER, THE RATIO IS OF 1:2, IN THE FORMER AND IN THE LATTER IT IS 1:1.
3. UNLIKE THROMBIN, BOTROPASE IS NOT ABSORBED BY THE FIBRIN CLOTS AND IS THEREFORE NOT NEUTRALISED BY THAT MECHANISM, AS OCCURS WITH THROMBIN.