Early reperfusion of an ischemic region can result in significant salv
age of the area at risk. We show the presence of hydroxyl free radical
s at the time of post ischemia reperfusion using electron paramagnetic
resonance (EPR) spectroscopy in a macaque model. These free radicals
may be formed as a result of reperfusion or may be an un-involved byst
ander. It is possible that they may be involved in reperfusion injury.