P2cyc-induced aggregation occurs without shape change in Gαq-deficient platelets.

SEM of WT (left panels) and Gαq-deficient mouse platelets (right panels). (A) 100 μmol/L ADP induced shape change and aggregation in WT platelets, whereas Gαq-deficient platelets did not change shape and formed comparatively smaller aggregates. (B) Addition of adrenaline (10 μmol/L) increased the size of these aggregates without modifying the platelet shape. (C) The P2cyc antagonist AR-C69931MX (10 μmol/L) inhibited aggregation in both WT and Gαq-deficient mouse platelets although not the shape change of WT platelets.