Figure 4.

Effect of tPA and reteplase on half-maximal effective concentration (EC₅₀) of PE in isometrically contracted aortic rings: EC₅₀ is defined as the PE concentration that induces 50% of the maximal contraction. While the full-length wild-type tPA (WT-tPA) exerts opposing pro-vasodilatory and vasoconstrictive effects at low (1 nM) and high (20 nM) concentrations, respectively (increasing and reducing EC₅₀ of PE, respectively), the delta kringle reteplase (DK-tPA), a tPA variant lacking kringle-1 and a finger domain, exerts vasodilation at both concentrations (^*P<0.001 vs control conditions – CTR).