PROLONGATION OF PT AND APTT UNDER EXCESSIVE ANTICOAGULANT IN PLASMA FROM RATS AND DOGS

Prothrombin time (PT) and activated partial thromboplastin time (APTT) were studied under excessive sodium citrate using the plasma from rats and beagle dogs. Addition of sodium citrate into the plasma caused a prolongation of PT and APTT. The prolongation was dependent on the concentration of sodium citrate or calculated hematocrit. The degree of prolongation was more severe in rats than in dogs, and in APTT than in PT. These results suggest that an artificial prolongation of PT and APTT occurs under excessive sodium citrate (e.g., elevated hematocrit), and that the degree differs between species and between parameters.