HUMAN PROTHROMBIN: QUANTITATIVE STUDIES ON THE PLASMA LABILE FACTOR AND THE RESTORATIVE EFFECTS OF NORMAL, HYPOFI-BRINOGENEMIC, AND HEMOPHILIC PLASMA ON THE PROTHROMBIN OF STORED PLASMA 1

Abstract

Quick (1) reported on the multiple na- ture of plasma prothrombin. On the basis of his data, which have been repeatedly confirmed (2-4), he concluded that prothrombin consists of two essential factors combined with calcium. The two components, "prothrombin A" and "prothrombin B," had different properties. The former was labile in oxalated or citrated plasma stored at re- frigerator temperatures, not adsorbable by alumi- num hydroxide, fairly heat stable, and not reduced in dicumarolized blood. Its deterioration was said to account for the high prothrombin time of stored plasma. "Prothrombin B," on the other hand, re- mained intact in refrigerated plasma, was re- moved by aluminum hydroxide, was labile at 600 C. for 15 minutes, and was decreased by the ad- ministration of dicumarol.