Antiplatelet effects of sodium nitroprusside in flowing human blood: studies under normoxic and hypoxic conditions.

Abstract We explored the ability of sodium nitroprusside to modify adhesive and cohesive function of platelets in flowing blood, under normoxic and hypoxic conditions. Aliquots of both untreated and sodium nitroprusside–treated blood were prepared for studies of: (1) platelet aggregation in plasma; (2) erythrocyte deformability; (3) platelet interaction with damaged subendothelium, by using a well-defined perfusion system; and (4) blood gasometry in the perfused samples. Results showed that sodium nitroprusside–treated blood always showed a totally inhibited arachidonic acid–induced platelet aggregation in plasma, as well as significantly increased erythrocyte deformability (0.44±0.09 up to 0.66±0.05; p −1 ), although it significantly reduced the height of thrombi (9.8±0.4 vs. 8.3±0.4 μm; p 2 in control untreated samples rose from 40.3±5.0 mm Hg perfusions to 100.4±12.5 mm Hg but remained at 66.3±6.3 mm Hg in sodium nitroprusside–treated blood ( p