Effect of adenosine derivatives on in vitro thrombus formation induced by shear stress.

BACKGROUND AND OBJECTIVE Shear-stress is considered to be the first event of platelet aggregation in vivo and platelet adhesion may be enhanced under pathologic conditions (e.g. arterial occlusion). DESIGN AND METHODS We wanted to test the effect of adenosine derivatives on platelet aggregation induced by shear-stress. By increasing platelet cAMP adenosine derivatives inhibit platelet activation. This in turn leads to P-selectin (CD62P) exposure, which is known to play a fundamental role in the binding of platelets to leukocytes. This gives rise to thrombus formation. RESULTS The levels of cAMP (pmol/mL) prior to and after treating blood with the following compounds were respectively: PGE1 4.67+/-0.29, 9.33+/-0. 58; SP64 5.2+/-0.34, 6.83+/-0.52; 2-Cl-adenosine 5.83+/- 0.58, 7. 45+/-0.55; NECA 7.00+/-2.29, 8.00+/-1.76. INTERPRETATION AND CONCLUSIONS High shear rate was studied using a filteraggregometer which could be a good test for analyzing what happens under physiologic conditions compared to other systems in which platelet aggregation only occurs after adding aggregating agents (Born aggregometer).