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

Abstract

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).