cAMP inducers decrease APS IgG–induced platelet activation and aggregation. Purified platelets were preincubated with A_2AR-i (5μM), A_2AR-a (5 μM), dibutyryl-cAMP (Dibut-cAMP, 0.5 mM), 8-Br-cAMP (1 mM), or forskolin (1 μM) for 20 minutes, followed by stimulation with 100 μg/mL cont IgG or APS IgG for 1 hour. (A-B) Platelets were then assessed for surface CD62P using flow cytometry, and (C) released ATP in the supernatant from the treated platelets using the luminescence-based assay. ∗P < .05, ∗∗P < .01, ∗∗∗P < .001, and ∗∗∗∗P < .0001, by a 1-way ANOVA with the Tukey multiple comparisons test (n = 4). (D) Representative immunoblots for (pAkt, Ser 473), total Akt, and GAPDH in the treated platelets (n = 3). (E and F) Representative curves and quantification of washed platelet aggregation in response to 100 μg/mL cont IgG or APS IgG treatment in the presence or absence of cAMP inducers, followed by stimulation with ADP (Effective concentration of 5-10 μM). Data represent mean ± SD. ∗∗∗∗P < .0001 and ns by a 1-way ANOVA with the Tukey multiple comparisons test (n = 5).