The effect of nitric oxide donors on the release of plasminogen activator inhibitor (PAI) from rabbit platelets in vitro.

Here we describe effects of four nitric oxide (NO) donors, 4-arylsubstituted oxatriazol derivatives and 3-morpholino-sydnonimine (SIN-1) at concentrations of 30-1000 microM on the release of plasminogen activator inhibitor (PAI) from rabbit platelets in vitro. At 37 degrees C, pH of 7.4 and a concentration of 30 microM, all compounds released NO as measured by the Werringloer's technique. The NO-generating potency of the compounds correlated with their capacity to inhibit the release of PAI from platelets and both phenomena were concentration-dependent. We conclude that various types of NO-donors activate plasma fibrinolytic system through inhibition of the release of PAI from platelets.