Figure 2.

Effects of flavonoids on thrombin-, PAR₁-AP- and PAR₄-AP-induced ¹⁴C-5-HT release. Platelets loaded with ¹⁴C-5-HT were incubated with flavonoids (50 µM) or LJ-CP8 (1 µM) and then stimulated under stirring conditions. Released radioactivity was measured in supernatants by liquid scintillation counting. Data (n= 4) are percentage of secretion versus the release obtained in stimulated control samples without flavonoids (dimethylsulphoxide). 5-HT release values (% vs. total radioactivity incorporated) in the samples without flavonoids upon stimulation with 0.2 U·mL⁻¹ thrombin, 25 µM PAR₁-AP or 150 µM PAR₄-AP were 88.5 ± 2.0, 65.7 ± 2.0 and 76.8 ± 11.7, respectively. *P < 0.05 versus the ¹⁴C-5-HT release induced by each agonist in untreated platelets.