Secretion of ATP and TxA2 in response to γ-thrombin is greatly diminished in Lyn-deficient platelets.

ATP secretion was measured by luminescence detection at a setting of 0.001X with the addition of 10 μL CHRONO-LUME reagent after the completion of aggregation and expressed as percent secretion. Because TxA2 has a half-life of 37 seconds and is rapidly converted to the stable product TxB2, TxA2 was measured as TxB2. Lyn-deficient platelets did not secrete ATP (A) or generate TxA2 (B) in response to a medium concentration of γ-thrombin. ATP secretion and TxA2 production were greatly diminished in response to high concentrations of γ-thrombin, though Lyn-deficient and wild-type platelets aggregated similarly.