Time course and dose response of aspirin inhibition of NO consumption by washed platelets in vitro. Aspirin-treated or -untreated platelets (room temperature, varying time and/or dose) were placed in the chamber of the NO electrode at 2 × 10⁸/mL in 500 μL Tyrode buffer containing 1 mM CaCl₂ at 37°C. NO (3.8 μM) was added, and decay was monitored, with and without addition of 50 μM arachidonate. (A) NO consumption rates were monitored following incubation with 1 mM aspirin for varying times. (B) NO consumption rates were monitored following incubation for 15 minutes with varying aspirin concentrations (mean ± SEM, n = 3).