Flavone-8-Acetic Acid (Flavonoid) Profoundly Reduces Platelet-Dependent Thrombosis and Vasoconstriction After Deep Arterial Injury In Vivo

Background—Flavone-8-acetic acid (FAA; [Flavonoid]), an adjuvant antitumor drug, inhibits ristocetin-induced aggregation of human platelets. The effect of FAA on platelet-dependent thrombosis was studied in vivo in the porcine carotid artery after deep arterial injury by balloon angioplasty. Methods and Results—111In-labeled autologous platelet and 125I-labeled porcine fibrin(ogen) deposition, and the incidence of macroscopic mural thrombosis onto deeply injured artery (tunica media) were compared in 20 pigs (40±1 kg [mean±SEM], body surface area=1.0±0.1 m2), randomized to FAA bolus (n=10) of 5.5g/m2, followed by an infusion at 0.14g · m−2 · min−1 or placebo (n=10). Vasoconstriction was measured immediately beyond the dilated segment using quantitative angiography. Platelet deposition (×106/cm2 of carotid artery) was reduced over 12-fold in pigs treated with FAA (13±3 versus 164±51, P=0.001) compared with placebo. Fibrin(ogen) deposition (×1012 molecules/cm2 of carotid artery) did not significantly differ...