Effect And Mechanism Of Agkistrodon Halys Venom Platelet Inhibitor On Hemorheology In Rats With Acute Myocardial Ischemia Reperfusion Injury

Objective: To explore effect of platelet inhibitor from Agkistrodon halys venom on changes of hemorheology indexes in model rats of acute myocardial ischemia-reperfusion injury and its possible mechanism involved.Methods: 1.Subgroup and Administration 30 matched SD Male rats were randomly divided into sham operation group(6 rats),myocardial ischemia-reperfusion injury(MIRI)model group(6 rats)and agkistrodon halys venom platelet inhibitor(AHV�PI)group(6 rats in group Low-AHV-PI,6 rats in group Medium-AHV-PI,the rest of rats in group High-AHV-PI).The Low-AHV-PI group was administrated 0.05 milligrams of AHV-PI for every kilogram of weight,the Medium-AHV-PI group was administrated 0.1 milligrams of AHV-PI for every kilogram of weight and the High-AHV-PI group was administrated 0.2milligrams of AHV-PI for every kilogram of weight.2.Model Preparation The model of MIRI rats were induced by ligaturing the anterior descending branch of the left coronary artery,While rats in AHV-PI group were pretreated by injection AHV�PI through sublingual vein before modeling.All rats in sham operation group were received thoracotomy only.Monitoring electrocardiogram(ECG)changes of all rats by RM6240 biological signal collection and processing system.The rat was immediately put to death when the experiment has been completed and then collected its heart tissue,HE staining was used to observe rat cardiac morphological changes.3.Index Detection Blood sampling from carotid artery of total rats were taken two hours after modeling.Viscosity of whole blood and plasma were measured by Cone plate hemorrheology analyzer.Blood coagulation time(R),blood clots forming time(K),Alpha Angle(A),and maximum amplitude of blood coagulation(MA)were assayed by Thrombelastography(TEG).Turbidimetry detected rate of platelet aggregation-A minute platelet aggregation rate(A1),three minutes platelet aggregation rate(A3)and five minutes platelet aggregation rate(A5),the maximum gathering time(tmax)and gathering range;while the expression level of blood plasma v WF,P-selectin and platelet membrane glycoprotein VI(GPVI)were measured by enzyme-linked immunosorbent assay(ELISA).Protein immunoblot method(Western bloting)was used to observation with and without AHV-PI intervention,whether did platelet membrane glycoproteins GPVI of rat in every group changes its expression level.Results: 1.The heart rate of every rat in sham operation group increased SD and rat of MIRI model group after cardiac ischemia its ecg displayed such as S-T raise up,T wave is also high,heart rate decreased.Pathological diagnosis on myocardial tissue from sham operation group,Medium-AHV-PI group and High-AHV-PI group indicated that myocardial cell swelling but they still arranged well without changes like absence,degeneration and necrosis;while MIRI model group and Low-AHV-PI group were detected rat myocardial swelling and myocardial cell nuclear pyknosis,crushing,dissolved.2.Compared with MIRI group,the whole blood high shear,medium shear and low shear viscosity and plasma viscosity in Medium-AHV-PI group and High-AHV-PI group were significantly decreased(P<0.05),value of R and K were significantly prolonged(P<0.05)while in numerical terms of A,MA,A1,A3,A5,Tmax and platelet aggregation range were also decreased in Medium-AHV-PI group and High-AHV-PI group(P<0.05).3.Both in Medium-AHV-PI group and High-AHV-PI group,the expression level of v WF?P-selectin and GPVI were also reduced extremely(P<0.05)when compared with MIRI group.In compared with sham operation group,difference in the whole blood viscosity,plasma viscosity,blood coagulation time(R),blood clots forming time(K),Alpha Angle(A),maximum amplitude of blood coagulation(MA),A1,A3,A5,Tmax,platelet aggregation range,expression level of blood plasma v WF,P-selectin and platelet membrane glycoprotein VI were not significant between Medium-AHV-PI group and High-AHV-PI group separately(P>0.05).When we statistical analyse between myocardial ischemia-reperfusion injury(MIRI)model group and Low-AHV-PI group,we found nothing discrepancy in all above values or expression levels mentioned(P>0.05),neither did we could recognize difference from systematic scrutinize between Medium-AHV-PI group and High-AHV-PI group(P>0.05).Conclusion: AHV-PI Medium administration and High administration can significantly attenuated damage of rats to myocardial ischemia-reperfusion injury.AHV-PI could effectively improved hemorheology indexes change in myocardial ischemia reperfusion injury rats such as reduce expression level of GP,inhibit high blood coagulation state occurred.Above all,we also found AHV-PI could attenuated the myocardial ischemia reperfusion injury in rats may by reduce the volume of v WF and P-selectin released together with decrease the expression level of GPVI on experimental rats platelets.