Abstract:

Abstract:Objective
 To study the protective effect of panax quinquefolium 20s-protopanaxtriolsaponins (PQTS) on acute myocardial infarction in rats,and to clarify its mechanism. Methods The acute myocardial infarct model was prepared by left anterior descending  coronary occulusion for 24 h in openchest anesthetized rats. The rats were divided randomly into sham group,ischemia-reperfusion model group and PQTS 12.5,25.0， and 50.0 mg•kg-1 groups. All animals were administered one time everyday with intraperitoneal injection(i.p) for 3 d. The myocardial infarct size (MIS) was calculated. The activities of serum creatine hosphokinase(CK),lactate dehydrogenase (LDH),aspartate aminotransferase (AST) and superoxide dismutase(SOD),and the contents of malondialdehyde(MDA),nitric oxide(NO) and free fatty acid(FFA) were determined. Blood was collected to observe low shearing specific viscosity,middle shearing specific viscosity and high shearing specific viscosity of whole blood and plasma viscosity. At the same time,the platelet aggregation rate was also determined. Results Compared with model group,the MIS  in the  rats treated by PQTS (in  dosages of 12.5,25.0 and 50 mg•kg-1•d-1,i.p×3 d) were significantly reduced(P<0.05);the activities of serum CK,LDH and AST,and the contents of serum FFA and MDA were declined(P<0.05 or P<0.01);the activitie of SOD,and the content of NO were increased markedly(P<0.05). In addition,the low shearing specific viscosity,middle shearing specific viscosity and high shearing specific viscosity of whole blood and plasma viscosity as well as platelet aggregation rates were also declined significantly(P<0.05 or P<0.01). Conclusion PQTS has a significant protective effect on acute myocardial infarction,which may be related to increasing the activity of antioxidase in body,scavenging the damage of peroxidation from oxygen free radicals,correcting metabolic disorder of FFA in myocardial ischemia,and decreasing the viscosity of blood and plasma and function of the platelet aggregation etc.

Key words: panax quinquefolium 20s-protopanaxtriolsaponins, acute myocardial infarction, myocardial enzymology, platelet function, free radicals, free radical, blood viscosity