Abstract
Male rabbits receiving single intravenous doses of leucine exhibit increase in the amounts of factors VII and IX and in prothrombin activity among the various coagulation factors in the circulating blood. The effects are due to mobilization, by the amino acid, of these factors which have already been formed. The results of the study herein described also seem to suggest that prothrombin is not merely a circulating precursor of thrombin but acts as an accelerator of thromboplastin formation.
