PLASMA PROTHROMBIN CONCENTRATION IN DOGS GIVEN 3,3'-METHYLENEBIS(4- HYDROXYCOUMARIN) AND PURIFIED BEEF PROTHROMBIN.

Purified beef prothrombin will antidote the hypoprothrombinemia induced in dogs by oral administration of 3,3'-methylenebis (4-hydroxyeoumarin). If the hypothesis is proven that this chemical compound acts only by preventing the production of prothrombin in the liver then the life of injected beef prothrombin is probably of the same duration as that of the dog's own plasma prothrombin; namely, 2 to 3 days.