Leukocyte involvement in cerebral infarct generation after ischemia and reperfusion.

White blood cell involvement in the generation of cerebral infarcts was evaluated following ischemia and reperfusion injury in the rat. Control and leukopenic rats (induced by vinblastine, WBC counts < 1500/mm3) were compared in a global forebrain ischemic model after 1 h of ischemia and 1 h 15 min of reperfusion. Cerebral infarcts were defined on coronal brain sections using Triphenyl tetrazolium chloride (TTC) staining. Electroencephalographic activity (EEG) and somatosensory evoked potentials (SSEP) were also compared. Results indicate that the area infarcted in leukopenic rats was significantly less than infarcts generated in corresponding controls (21 +/- 16% vs. 70 +/- 16%). In addition, EEG was preserved in all leukopenic animals when compared to controls, both during ischemia and after reperfusion. The cortical peak component of the SSEP was also better preserved in the leukopenic animals both during ischemia and at 60 min of reperfusion. These results indicate white blood cell participation in the generation of cerebral damage in a model of global forebrain ischemia and reperfusion as indicated by TTC staining of cerebral infarcts.