OBJECTIVETo establish and evaluate a hypercoagulable animal model for the assessment of anticoagulants.

METHODSForty mice, thirty-two rats, and twenty-four rabbits were randomly and equally divided into control group (saline) and three ellagic acid (EA)-treated groups (low, middle, and high doses). In the mice, bleeding time (BT) was estimated with tail transaction, and clotting time (CT) with template method. Prothrombin time (PT) and the activated partial thromboplastin time (APTT) in rats and rabbits were measured by means of Quick's one-stage assay and modified APTT assay respectively. In addition, thrombin activity was estimated in rats with PT assay using a hemagglutination analyzer. The circulating platelet aggregates were detected in rabbits through platelet counting and presented as the circulating platelet aggregate ratio (CPAR).

RESULTSEA shortened BT and CT in mice, PT and APTT in rats, and increased thrombin activity and CPAR, all in a dose-dependent manner. EA also brought reduction of PT and APTT in rabbits in dose- and time-dependent manners.

CONCLUSIONEA could induce hypercoagulable state through activating coagulation system and platelets in mice, rats, and rabbits.