Therapeutic window of taurine against experimental stroke in rats.

The dose-dependent protection of taurine against experimental stroke has been demonstrated previously. The objective of this study was to investigate the therapeutic window of taurine against experimental stroke, and the effects of delayed administration of taurine on inflammatory reaction in a rat model of stroke. Rats received 2-h ischemia by intraluminal filament, and then reperfused. Taurine (50 mg/kg) was administered intravenously 4 h, 8 h, 10 h, or 12 h after ischemia. The neurologic scores and the infarct volumes were evaluated 24 h after ischemia. Then, the effect of administration of taurine at 8 h after ischemia on the neutrophil infiltration in ischemic region was determined. Treatment with taurine 4 h or 8 h after ischemia significantly improved the neurologic function, and decreased the infarct volumes 24 h after ischemia. However, administration of taurine at 10 h or 12 h after ischemia had no significant neuroprotection. Further, taurine administered at 8 h after ischemia markedly reduced myeloperoxidase activity and attenuated neutrophil infiltration in ischemic region. Our data suggest that the therapeutic window of taurine against experimental stroke is of at least 8 h, and suppressing the neutrophil infiltration may be one of the mechanisms of delayed administration of taurine against experimental stroke.