Figure 1. Rt-PA treatment disrupted the BBB in vivo after I/R. (A) Schematic of the animal study design. (B) Water content of the ipsilateral hemispheres and contralateral hemispheres of the brains of mice treated with or without 9 mg/kg rt-PA 1 d after I/R; ips: ipsilateral hemisphere; con: contralateral hemisphere; n = 6 for each group. Data represent the mean ± sd; *p < 0.05, **p < 0.01. (C) Electron microscopy was used to study the BBB ultrastructure of the sham-treated mice and mice 1 d after I/R treatment with or without 9 mg/kg rt-PA; scale bar: 4 μm. PC: pericyte, EC: endothelial cell; As: astrocyte; TJ: tight junction. The thin arrow indicates mitochondria; the thick arrow indicates the basement membrane. (D, E) Representative immunofluorescence images of Ki-67 protein expression in the pericytes of the sham-treated mice and mice 1 d after I/R treatment with or without 9 mg/kg rt-PA; scale bar: 50 μm; n = 3 for each group. Data represent the mean ± sd *p < 0.05, **p < 0.01.