Effect of tPA on rat hemodynamics. Blood pressure and cortical cerebral blood flow were monitored in anesthetized rats given intravenous tPA alone (tPA) or in combination with the PAI-1–derived peptide EEIIMD (tPA + EEII) or TNK-tPA (TNK-tPA). Cerebral vascular resistance was extrapolated from the corresponding changes in blood pressure and regional flow. Values are presented as mean ± SEM. In tPA-treated rats but not in the other 2 groups, blood pressure and cerebral vascular resistance significantly declined. (*P < .05 vs baseline, ANOVA).