Effect of P2 receptor antagonists on ADP-induced thromboxane A2 generation.
Human platelets were activated after adding fibrinogen (3 μM) with the ADP(10 μM) in the presence or absence of various concentration of AR-C67085 (panel A) or A2P5P (panel B), as indicated, at 37°C with stirring at 900 rpm. Reactions were stopped at 3 minutes after the addition of ADP by snap-freezing the samples. Thromboxane B2 was measured by means of an EIA as described in “Materials and methods.” The thromboxane B2 values were normalized to those in the absence of the antagonist (taken as 100%). The data are derived from at least 3 independent experiments. The curves represent hyperbolae that best fit the data with the use of the program Kaleidagraph (Synergy Software, Reading, PA).
