ABSTRACT
AIM:To explore effect and meaning of Agkistrodon halys venom platelet inhibitor on GPVI expression and hemorheology in rats with acute myocardial ischemia reperfusion injury. METHODS: Thirty 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(18 rats). The AHV-PI experimental group was divided into low, middle and high dose groups according to the dose of AHV-PI injected into sublingual vein (0.05, 0.1, 0.2 mg/kg), with 6 rats in each group. Electrocardiogram(ECG) changes of rats were monitored by RM6240 biological signal collection and processing system. Western blot was used to monitor the expression of platelet membrane glycoprotein VI (GPVI) in rats under the intervention of AHV-PI. Blood coagulation time (R), blood clots forming time (K), Alpha Angle (A), and maximum amplitude of blood coagulation (MA) were assayed by Thrombelastography (TEG5000).Platelet aggregation rate was measured by turbidimetry. RESULTS:Compared with MIRI model group, the expression level of GPVI AHV-PI medium dose experimental group and high dose experimental group were significantly decreased (P<0.05), and the R and K values were significantly prolonged, while the A value and MA values were significantly decreased (P<0.05). Platelet aggregation time, aggregation amplitude and aggregation rate were significantly decreased (P<0.05). CONCLUSION: AHV-PI can significantly inhibit the expression of GPVI in MIRI rats and improve the hemorheological properties related to myocardial injury in rats, thus weakening the injury process.
ABSTRACT
Objective To investigate the mechanism of platelet inhibitor from Agkistrodon halys venom (AHV-PI) on platelet aggregation. Methods Protein kinase Akt phosphorylation levels in platelet were measured by Western blot. XS-1000I blood cell counter was used for platelet count. The plasma content of 5'-NT and platelet membrane GPIb were determined by Enzyme-Linked Immunosorbnent Assay (ELISA). The effect of AHV-PI on binding rate between the fluorescence labeled monoclonal antibody CD61 (FITC-CD61) and platelet membrae glycoprotein Ⅱb/Ⅲa (GPⅡb/Ⅲa) was observed by flow cytometry (FCM). Results AHV-PI can reduce the level of Akt-phosphorylation level and the number of platelet. AHV-PI can increase the content of 5'-NT in plasma, reduce the expression of platelet GPIb. Flow cytometry displayed AHV-PI can not affect the rate of combination between platelet GPⅡb/Ⅲa and FITC-CD61. Conclusion The mechanism of inhibition of platelet aggregation may be inhibit protein kinase Akt phosphorylation to block the signal transduction pathway of Akt. Limit cell grouth and reduce platelet number, also it may be related to its 5'-NT activity, it can degradate ADP to prevent the formation of platelet thrombus.