Abstract: AIM: To compare Yinxingdamo injection with Shuxuening injection on hemorheology and plasma levels of superoxide dismutase (SOD), malondialdehyde (MDA) and nitrogen monoxidum (NO) in aged rats. METHODS: 24 aged rats were randomly divided into 4 groups:control, Yinxingdamo group, Shuxuening group and dipyridamole group.The ratswere givenNS, Yinxing-damo injection, Shuxuening injection and dipyridamole, respectively.The administration dosages were 2 ml·kg^-1, once everyday for 7 d successively.Another six normal young rats were arrayed into normal control.Hemorheolo-gy and plasma levels of SOD, MDA and NO were mea-sured.RESULTS: After intraperitoneal injection of Yinxingdamo for 7 days, the level of SOD in plasma of aged rats increased (P<0.05) and the level of MDA de-creased (P<0.01), the whole blood viscosity (at high shear rate) and contents of fibrinogen decreased (P<0.05) compared with those of control group.The level of SOD in plasma of aged rats increased obviously (P<0.05), the whole blood viscosity (at high or lower shear rate) and content of fibrinogen decreased (P<0.05) in Shuxuening group compared with those in control group. After intraperitoneal injection of dipyridamole injection, content of fibrinogen decreased (P<0.01) and index of red blood cell deformation increased (P<0.05) com-pared with those of control group.Plasma NO contents showed a tendency to decrease, but there was no signifi-cant statistical difference between either two groups. There was also no obvious difference on hemorheology and levels of SOD, MDA andNO in plasma between Yinxing-damo group and Shuxuening group (P >0.05).CONCLUSION: Changes of hemorheology in aged rats can be improved with Yinxingdamo or Shuxuening, the level of SOD increases and the level of MDA decreases.The re-sults suggest that the two drugs have effects of anti-aging, anti-oxidation, dilating coronary vessels and cerebral ves-sels and improving the symptom of cerebral ischemia, which may be the pharmacological foundation of prevent-ing and treating high-incidence diseases among aged peo-ple of these two drugs.

Key words: ginkgo bilobo extract, dipyridamole, aged rat, SOD, MDA, NO, hemorheology