Isolation and washing of human platelets with nitric oxide.

Nitric oxide (NO) was compared with prostacyclin as an inhibitor of the activation of human platelets during isolation, washing and storage. The use of NO throughout the procedure prevented the activation of platelets. The morphology and behaviour of NO-washed platelets was similar to that of prostacyclin-washed platelets when stored at 4 degrees C for up to 24 h. Prolonged storage resulted in deterioration of the platelets which occurred earlier in the NO-washed than in the prostacyclin-washed platelets. The protective effect of NO was potentiated by the selective cGMP phosphodiesterase inhibitor M & B 22948, suggesting that it is mediated by the activation of guanylate cyclase.