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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.
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OBJECTIVE Salvia miltiorrhiza bunge contains various active constituents, some of which have been developed as commercially available medicine. Moreover, some other ingredients in Salvia miltiorrhiza play great roles in anti-platelet activity. The aim of the present study was to investi-gate the effects and the underlying mechanism of miltirone,a lipophilic compound of Salvia miltiorrhiza Bunge. METHODS The ability of miltirone to modulate platelet function was investigated by a variety of in vitro and in vivo experiments.Platelet aggregation and dense granule secretion induced by various agonists were measured with platelet aggregometer.Clot retraction and spreading were imaged by digital camera and fl uorescence microscope. Ferric chloride-induced carotid injury model and pulmonary thromboembolism model were used to check miltirone effect in vivo. To elucidate the mechanisms of anti-platelet activity of miltirone,flow cytometry and Western blotting were performed. RESULTS Miltirone (2,4,8 μmol·L-1)was shown to suppress platelet aggregation,dense granule and α granule secretion in a dose-dependent manner. Meanwhile, miltirone inhibited the clot retraction and spreading of washed platelets.It reduced the phosphorylation of PLCγ2,PKC,Akt,GSK3β and ERK1/2 in the down-stream signal pathway of collagen receptor.It also reduced the phosphorylation of Src and FAK in the integrin αⅡbβ3 mediated"outside-in"signaling,while it did not suppress the phosphorylation of β3.In addition, miltirone prolonged the occlusion time and reduced collagen/epinephrine induced pulmonary thrombi. CONCLUSION Miltirone suppresses platelet "inside-out" and "outside-in" signaling by affecting PLCγ2/PKC/ERK1/2, PI3K/Akt and Src/FAK signaling. Therefore, miltirone might represent a potential anti-platelet candidate for the prevention of thrombotic disorders.
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by lfow cytometry. According to CAG morphology, the plaques included 3 types as Type I, Type II and TypeⅢ. The patients also received coronary CT angiography (CTA), upon CTA value, the plaques were classiifed by soft plaque, ifbrous plaque and calciifed plaque. Expressions of platelet surface EMMPRIN and GPVI among different groups were compared. Results:①Compared with Control group, ACS and SAP groups had increased expressions of EMMPRIN (5.82 ± 0.81 and 3.45 ± 0.48) vs (1.35 ± 0.15) and GPVI (16.22 ± 5.27 and 8.20 ± 2.87) vs (4.14 ±1.17); the expressions in ACS group were higher than those in SAP group, allP Conclusion: Expression levels of platelet surface EMMPRIN and GPVI were closely related to the stability of coronary plaque, both of them were the risk factors for severe coronary lesions. EMMPRIN and GPVI may have certain predictive value for early diagnosis of arteriosclerosis in ACS patients.