Abstract:

The inhibitory effect of ilexonin A(IA)on platelet aggregation in vitro and in vivo induced By adengsine diphosphate(ADP)whichactivates platelet function was studied in this paper.The effect of IA onprostacyclinlike substances was also investigated.Basing on in vivostudy,our result suggested that IA was an inhibitor of arachidonicacid(AA)which activated platelet function in another way.Meanwhile,IA inhibited the way by which ADP activated platelet function in vitroand in vivo.In further study with radioimmunassay,we measured theplasma levels of thromboxane B₂(TXB₂)and 6-keto-PGF₁ in rabbit.Theantithrombotic agent might be caused through the stimulation action ofIA of prostacyclin production from arterial endothelium in vivo.In vitroand in vivo experiments showed that nitroglycerin(NTG)had inhibitoryeffects both on ADP and AA.It also enhanced the inhibitory effect ofPGI₂-like substances on platelet aggregation.It was suggested that NTGexerted its regulating effect on TXA₂/PGI₂ balance.In the acutely lethalexperiment,both IA and NTG had apparent protective effects.