Myeloperoxidase activity as an indicator of leukocyte infiltration into the ischemic area in the middle cerebral artery occlusion model of the rats

: Myeloperoxidase was solubilized with hexadecyltrimethylammonium bromide and myeloperoxidase activity was measured with a dianisidine-H2O2 assay in the ischemic area after middle cerebral artery occlusion in rats. This enzyme could be measured 6 hours after the occlusion of the middle cerebral artery, then showed two peaks, one after 8 hours and another after 18 to 24 hours in 2 phase fashion as could be measured as far as 7 days, which was the termination of this experiments. These findings suggest that leukocyte infiltration into the ischemic area play an important role for the extension of the ischemic area. Further study should undertake whether leukocyte depletion decrease the ischemic area or not.