Effect of OGD and of t-PA treatment on MMP-3 secretion by bEnd.3 cells. MMP-3 secretion from bEnd.3 cells after 6 hours of OGD followed by 18 hours of normoxia (O) in the absence or the presence of different concentrations of t-PA is monitored by Western blotting. Data are compared with bEnd.3 cells kept on normoxia (N) for 24 hours. Representative immunoblots (A,C,E) and quantitative data are as fold increase (B,D,F) of the effects of different concentrations of t-PA (A-B), active site-blocked t-PA (B), pretreatment with RAP (C-D), or an anti-LRP antibody (E-F) are also shown. Data represent mean ± SD of 4 to 9 experiments. *P < .05; **P < .01.