Can we use adenosine diphosphate (ADP) to study “aspirin resistance”?
There is a growing number of contradictory reports indicating that adenosine diphosphate (ADP) can be a useful agonist in monitoring of the antiplatelet action of acetylsalicylic acid (ASA) in humans and animals. In the current study, we aimed to determine the conditions for using ADP to trigger platelet aggregation in order to detect ASA-mediated inhibition of rat platelet reactivity. Initially, we examined the usefulness of different ADP concentrations (0.25, 0.5, 1, 5 and 10 microM) in detecting the in vitro ASA mediated platelet inhibition using whole blood aggregometry, as well as we monitored the role of ADP in generation of thromboxane A(2) (TXA(2)). To study ex vivo ASA inhibitory potential on platelet aggregation induced by a range of ADP concentrations, animals were subjected to one or 10-day ASA administration at the dose of 50 mg/kg. Our experiment shows that ADP in a concentration-dependent manner induces TXA(2) generation in the whole blood with hirudin as an anticoagulan
