Discussion

Abstract

I would like to congratulate Dr. Esnouf on his studies in this area of coagulation. Most investigators agree that the conversion of prothrombin to thrombin is probably achieved enzymatically by factor x_a and that factor v, in a reactive form, acts as some sort of co-factor or accelerator. Dr. Breckenridge and Dr. Ratnoff originally suggested that activated factor v was the final prothrombin converting principle. They found that when they incubated factor x, activated by Russell’s viper venom, phospholipid, calcium, and factor v, there was a time-consuming reaction when increasing activity of the pro-thrombin converting principle was generated (figure i, line A). They concluded that factor x_a was activating factor v.