Abstract
Background and Purpose— Microglial activation may contribute to the pathogenesis of the brain injury in intracerebral hemorrhage (ICH). We have reported that the tripeptide macrophage/microglial inhibitory factor (MIF), Thr-Lys-Pro, inhibits microglial activation and results in functional improvement when given before the onset of hemorrhage. In this study, we investigate the protection and efficacy of treatment when MIF is administered 2 hours after collagenase injection. Methods— ICH was induced by injecting bacterial collagenase into the caudate nucleus; 100 μL MIF (500 μmol/L) was delivered via a micro-osmotic pump. Infusion of MIF or saline (control) was initiated 2 hours after collagenase injection and continued for 24 or 72 hours. Microglial activation and macrophage infiltration were assessed by 5-d-4 and F4/80 immunofluorescence, respectively. Production of reactive oxygen species was visualized by in situ detection of ethidium. Degenerating neurons were assessed by Fluoro-Jade B staining. Neurol...