p53, bcl-2 Protein expression and the level of cerebral blood flow at the ischemic penumbra in rats

We investigated the spatial characteristics of apoptotic genes expression and CBF at the ischemic penumbra. A delayed focal cerebral infarction was created in twelve adult Sprague-Dawley rats. Immunohistochemical staining of bcl-2 and p53 proteins and TUNEL staining for apoptosis were performed. The peri-infarct area was divided into six sectors by distance from the infarction border. Local CBF was measured at 2 mm distal to the presumed MCA occlusion site preoperatively, and at 2 mm and 8 mm distal to the MCA occlusion site intraoperatively. TUNEL-positive, bcl-2 or p53 positive cells were concentrated as it went closer to the infarction core and reduced peripherally, which was inversely proportional to the local CBF. The area encompassed by the border of the p53 area was 3.3 ± 0.2 times of the infarction core. The p53 area seems to overlap the ischemic penumbra, and may deserve to be a molecular penumbra.