Figure 3.

Stimulation of platelet aggregation and inhibition of cAMP formation by epinephrine. (A) Aggregation was measured in response to a combination of 0.2 μM ADP plus epinephrine at the final concentrations indicated. As is shown in Fig. 2, epinephrine did not stimulate aggregation when added alone. The results shown are representative of two experiments. (B) The ability of epinephrine to inhibit PGI₂-stimulated cAMP formation was measured. The results are expressed as percent inhibition of cAMP formation in the absence of epinephrine. The results shown are the mean ± SEM from two experiments.