Synergistic antiplatelet action of nitric oxide (NO) with PGD2 and its metabolite PGJ2--relevance for cerebral circulation?

The PGI2/NO axis is well accepted for its central regulatory role in maintaining haemostatic balance in large arteries. Earlier findings suggest that PGD2 may also play a role in haemostatic regulation of human cerebral circulation. We therefore wondered whether PGD2 and its metabolite PGJ2 synergise in-vitro with NO. We approached this question using platelets of ten healthy donors and ADP as aggregation-inducing stimulus. Both PGD2 and PGJ2 do inhibit ADP-induced platelet aggregation in a dose-dependent manner. Platelet aggregation findings demonstrate that PGD2 and NO synergise, as does the metabolite PGJ2. Our data are indicative that the PGD2/NO and, in less extent, PGJ2/NO synergism might be of special importance for the cerebrovascular haemostatic control.