Antagonistic Effect and Mechanism of a New Derivative of Gingkolide B on Platelet Aggregation

AIM: To study antagonistic effect and mechanism of a new derivative of ginkolide B named XQ on platelet aggrega-tion. METHODS: To assay inhibiting effect of XQ on PAF-induced platelet aggregation with turbidimetry method, rabbits were ad-ministered at different final concentrations via iv at different times. The specific binding of I3HIPAF to rabbit platelet receptor was investigated by radio ligand binding assay (RLBA). RESULTS: Three groups (1.95, 3.9, 7.8 mg.kg-j) had significant effect on inhibiting PAF-induced platelet aggregation in rabbits, and inhibition ratio were 29.8%, 43.5% and 55.2% respectively (compared to normal group, P<0.01) The equilibrium dissociation constant (KD) and maximum binding capacity of [3H]PAF were 8.31×10-5 competitively occupying specific PAF receptor site on blood platelet membrane.