AIM To study whether APLA 2 Ⅰ is a candidate of antithrombotic drug. METHODS Model group rats were
pretreated with
iv(sublingual) PBS, three dose group of APLA 2 Ⅰ
pretreated rats were pretreated with iv(sublingual) APLA 2 Ⅰ 1.0, 0.5, 0.1 mg·kg -1 for 30 min,
respectively. Then the abdominal aortic thrombosis of rats induced by 40% FeCl 3 . The distal abdominal aortic pressure(AAP) of rats was monitored continually to take lowest AAP and thrombosis time. Thrombus area and thrombus weight were measured. Effect of APLA 2 Ⅰ on plasma clot retraction was investigated by the method of rat blood plasma clot retraction in vitro . Effect of APLA 2 Ⅰ on hemorrhage time was investigated by the method of mouse cauda arterial hemorrhage. RESULTS Pretreatment with iv APLA 2 Ⅰ 1.0, 0.5 , 0.1 mg·kg -1 can inhibit the dropping of distal AAP due to the thrombosis induced by FeCl 3, the lowest AAP was raised from (4.0±0.5) kPa (model group) to (7.7±1.0), (6.8± 0.8) , (5.4±0.7)kPa, respectively; the thrombosis time was extended from (31±4) min (model group) to (60±7), (53±5), (49±6)min, respectively; the thrombus area was reduced from (1062±139)μm 2 (model group) to (724±74), (785±96), (910±126)μm 2, respectively; the thrombus weight in 0.5 cm blood vessel section was decreased from (5.2±0.6)mg (model group) to (3.5±0.5), (3.8±0.5), (4.6± 0.6)mg , respectively. In vitro APLA 2 Ⅰ can inhibit the rat plasma clot retraction dose dependently. When mice were pretreated with ip APLA 2 Ⅰ 1.0, 0.5, 0.1 mg·kg -1 for 1 h, the caudal arterial hemorrhage time was prolonged from (1.4±0.4)min (control group ip PBS) to >10 , >10, (7.5±1.8)min, respectively. CONCULUSION APLA 2 Ⅰ can inhibit arterial thrombosis induced by FeCl 3 in rats.