Cyclooxygenase-2 immunoreactivity in the human brain following cerebral ischemia

The prostaglandin synthesizing enzyme cyclo-oxygenase-2 (COX-2) is up-regul ated in the brain of rodents during cerebral ischemia and contributes to is chemic brain injury. This study sought to determine whether COX-2 is also u p-regulated in the human brain in the acute stages of cerebral ischemic inf arction. Paraffin-embedded sections from patients who died 1-2 days followi ng infarction in the middle cerebral artery territory were processed for CO X-2 immunohistochemistry. COX-2 immunoreactivity was observed in infiltrati ng neutrophils, in vascular cells and in neurons located at the border of t he infarct. The data suggest that COX-2 up-regulation is also relevant to c erebral ischemia in humans and raise the possibility that COX-2 reaction pr oducts participate in the mechanisms of ischemic injury also in the human b rain.