| Objective: To investigate the effects of germidine on thrombosis, hemorrheology, platelet aggregation and blood coagulation in animals in order to provide experimental basis for its development as a highly efficacious antithrombotic agent.Methods and Results:1. Determination of LD50iv of germidine in mice:Fifty mice were randomly divided into 5 groups (10 mice each), germidine(5.22,6.14,7.23,8.50 mg.kg-1) was injected to mice at doses of 5.22,6.14,7.23,8.50 mg.kg-1. For negative control, mice were injected with NS instead of germidine. Based on the 7-d mortality in each group, LD50iv of germidine was caculated by Bliss method as 6.6619 mg.kg-1, with 95% confidence interval as 5.6120 mg.kg-1～7.9080 mg.kg-1.2. Effect of germidine on thrombosis in rats : The anti-artery thrombosis effect of the drug was examined in electricity-induced carotid thrombosis model rats. The occlusion time (OT) was recorded. The results showed that , germidine 1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1,10.00μg.kg-1 , 20.00μg.kg-1 and LAS18.0mg.kg-1(positive control) increased OT respectively as compared with NS nective control by 16.4%(P<0.05),27.3%,33.8%,43.9%,66.0%(P<0.01)and 52.3%(p<0.01).3. Effect of germidine on venous thrombosis in rats:The stasis-induced inferior vena cava thrombosis model were made according to Reyers'method. The effect of germidine was evaluated in terms of thrombus formation rate and the decrease in thrombus dry weight.NS was given as negative control while heparin as positive control. The results showed that germidine(1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1,10.00μg.kg-1 and20.00μg.kg-1) and heparin400.0μg.kg-1 lowered the thrombus dry weight by 7.0%(P>0.05),58.8%,70.4%,72.9% ,83.0%(P<0.01)and 85.0%(p<0.01).4. Effect of germidine on platelet aggregation4.1 Effect of germidine on in vitro rat platelet aggregation: The blank blood of rats untreated with drug were collected ,platelet rich plasma(PRP) and platelet poor plasma(PPP) were prepared by routine procedures. ADP was used as platelet aggregation inducer.Platelet aggregation curves were recorded in in vitro rats according to the method of Born.And then the percentage of platelet aggregation was calculated.The results showed that,germidine 6.25μg/L,12.50μg/L,25.00μg/L,50.00μg/L and LAS 40.0mg/L lowered ADP-induced platelet aggregation by 19.39%,33.55%,46.14% ,61.26% and 42.23% respectively.4.2 Effect of germidine on ex vivo rat platelet aggregation: The blood were collected from rats receiving iv administration of germidine at different doses.Platelet aggregation curves were recorded ex vivo rats according to the method of Born.And then the percentage of platelet aggregation was calculated.The results showed that,germidine 2.50μg.kg-1,5.00μg.kg-1,10.00μg.kg-1 ,20.00μg.kg-1 and LAS 18.0mg.kg-1 lowered ADP-induced platelet aggregation by22.67%,39.87%,47.39%,62.93%(P<0.01)and 47.21%(p<0.01)。5. Effect of germidine on clotting time (CT) in rats : Effects of germidine (1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1,10.00μg.kg-1 and 20.00μg.kg-1) on clot time in rats were observed at 20min after administration. NS was given as negative control while heparin as positive control. The results showed that germidine (1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1,10.00μg.kg-1 and 20.00μg.kg-1) increase CT by -0.81 %(P>0.05),119.14%,159.92%,228.74%,195.14%(P<0.01) while the increase of CT by heparin 1.25mg.kg-1 was 61.13%(p<0.01)。6. Effects of germidine on bleeding time (BT) in rats:Effects of germidine(1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1and 10.00μg.kg-1) on BT in rats were observed at 20min after administration. NS was given as negative control while heparin as positive control. The results showed that germidine(1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1and 10.00μg.kg-1) increase BT by47.13%,58.05%,121.84%and 105.17%(P<0.01)as compared with78.16% for heparin 1.25mg.kg-1.7. Effect of germidine on hemorrheology in rabbits : Germidine (1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1and 10.00μg.kg-1) or NS was injected into the ear marginal vein of rabbits, then the blood was collected from heart.The important hemorrheological indices were measured. The results showed that ,as compared with NS, germidine (1.25μg.kg-1,2.50μg.kg-1,5.00μg.kg-1and 10.00μg.kg-1) decrease the whole blood viscosity and plasma viscosity(P<0.05 orP<0.01).Conclusion:Germidine has powerful antithrombotic effects on artery thrombosis and venous thrombosis in rats, which are related to its antiplatelet, anticoagucant and blood viscosity-lowering effects;Germidine is one of the important antithrombolic compounds of VnA. |
PDF Full Text Request