Objective: To screen active fractions of Siwu Tang for activating blood and removing stasis by comparing their effects on the blood rheology

function of blood coagulation and platelet system of the acute model rats. Method: After Siwu Tang was boiled with water

the system solvent extraction method was adopted to extract four fractions respectively. Totally 80 female SD rats were divided into eight groups:the control group

the model group

the Compound Danshen dropping pill group (0.15 g · kg-1)

the Siwu Tang group (7 g · kg-1)

the Petroleum ether extract group (7 g · kg-1)

the Ethyl acetate extract group (7 g · kg-1)

the N-butyl alcohol extract group (7 g · kg-1) and the water extract group (7 g · kg-1). Except for the normal group

the ice water bath and subcutaneous injection with adrenaline hydrochloride were applied in all of the rest groups to establish the acute blood stasis rat model

in order to compare different extracted fractions in the hemorheology of rats after the administration

prothrombin time(PT)

thrombin time(TT)

activate parts thrombin time(APTT)

fibrinogen(FIB)

platelet aggregation rate

plasma thrombox-ane B2(TXB2) and 6-keto-prostaglandin Fla(6-keto-PGFla). Result: Compared with the normal group

the model group showed significant decreases in the shear rate of whole blood viscosity

plasma viscosity

TT

PT

APTT and 6-keto-PGFla and significant increases in FIB

platelet aggregation rate

plasma TXB2.Compared with the normal group

ethyl acetate fractions of Siwu Tang can significantly reduce the shear rate of whole blood viscosity

plasma viscosity

significantly extend TT

PT

APTT

significantly reduce FIB

platelet aggregation rate

plasma TXB2

elevate 6-keto-PGFla;the Petroleum ether group can notably decrease the whole blood viscosity at a high shear rate (P <0.05)

reduce TXB2 content

increase 6-keto-PGFla content (P <0.01);N-butyl alcohol fractions and water extracts can obviously reduce TXB2 and increase 6-keto-PGFla (P <0.01). Conclusion: Ethyl acetate fractions of Siwu Tang have the most effective effect in removing blood stasis.