NITROSYL HEMOGLOBIN PRODUCTION DURING REPERFUSION AFTER FOCAL CEREBRAL-ISCHEMIA IN RATS

We first detected a definite nitrosyl hemoglobin (HbNO) signal in the jugular blood by electron spin resonance spectroscopy during early rep erfusion after cerebral ischemia. A distinct three-line hyperfine stru cture, characteristic to HbNO, was demonstrated at 30 min of recircula tion after 2 h of middle cerebral artery occlusion in rats. Only a wea k HbNO signal was observed in animals with 2 h sustained ischemia or w ith sham operation. The present findings suggest that reperfusion afte r cerebral ischemia facilitates nitric oxide generation in the brain, which leads to the increased nitrosylation of erythrocyte hemoglobin i n the cerebral circulating blood.