IMMUNOHISTOCHEMICAL DETECTION OF NITROTYROSINE IN POSTISCHEMIC CEREBRAL-CORTEX IN GERBIL

We examined whether or not nitration of tyrosine residues takes place in the ischemic and postischemic reperfused brain. The nitration of ty rosine residues to produce nitrotyrosine is a sensitive marker elicite d by peroxynitrite, a powerful oxidant formed by the reaction of nitri c oxide (NO) with superoxide. Mongolian gerbils were subjected to 60 m in ischemia induced by occlusion of the right common carotid artery (i schemia group), to 30 min recirculation following 60 min ischemia (rep erfusion group) or to sham surgery (sham group). Immunohistochemical s taining with polyclonal anti-nitrotyrosine antibody revealed the wides pread and distinct occurrence of nitrotyrosine in cortical neurons on the reperfused side of the brain in the reperfusion group, while only partial or weak immunoreactivity was noted on the contralateral side. On the other hand, nitrotyrosine was not detected in the brain of the ischemia and sham groups. These findings suggest that nitration of tyr osine residues in various proteins may be closely associated with repe rfusion injury of the brain. (C) 1997 Elsevier Science ireland Ltd.