Rt-PA increases endogenous u-PA following experimental focal cerebral ischemia

The aim of this study was to investigate the effects of different doses of exogenous recombinant human tissue plasminogen activator (rt-PA) on the endogenous cerebral plasminogen/plasmin system in focal ischemia. Ischemia was induced using the suture model in rats subjected to 3h ischemia (I) and 24h reperfusion (R). Each group of rats (n=6) received either treatment (0.9, 9, or 18mg rt-PA/kg body weight) or saline (control group) at the end of ischemia; in addition a sham-operated group of rats (n=6) was involved in the comparisons. The activity of the plasminogen activators was measured by casein dependent pla…