Identification of a coagulopoietin for prothrombin.

A coagulopoietin specific for factor II has been demonstrated in the rabbit, and termed 'coagulopoietin-II'. A goat antiserum was used to lower the factor II level in a rabbit. When plasma from this rabbit was then injected into other rabbits, factor II rose in the recipients without increase in other coagulation factors measured (V, VII, and X). The coagulopoietin is stable to boiling for 30 minutes, and appear to have a molecular weight of less than 30,000.