The Level of Cerebral Blood Flow, p53 and p21 Expression at the Penumbric Area of Cerebral Infarction in Rats

ABSTRACT

OBJECTIVE: We report an investigation of cerebral blood flow(CBF) and the expression of p53 and p21 at peri-infarct area of focal cerebral infarction in rats. METHODS: Adult Sprague-Dawley male rats were used for the experiment. In Group 1(n=7), the right middle cerebral artery(MCA) was coagulated. In Group 2(n=11), the right MCA and common carotid artery(CCA) were coagulated, and the left CCA was occluded for 30 minutes. Cerebral blood flow was measured at two areas, 2mm and 8mm distal to the MCA coagulation site. The rats were killed after 24 hours. After immunohistochemical staining, the width of the p53 or p21 positive area was measured. The p53 and p21 positive glial cells were counted at the peri-infarct area adjacent to the infarction core in Group 2. RESULTS: A focal infarction was found invariably in Group 2. CBF's at 2 mm and 8 mm areas were 8.3+/-2.1, 36.4+/-4.2 in Group 1 and 0.0+/-0.0, 6.7+/-1.5ml/100g/min in Group 2, respectively. All of the measured CBF's except that of the 8mm site in Group 1 were significantly lower than preoperative level(p<0.001), which were between 20.8+/-4.5% and 16.3+/-3.3% of preoperative CBF. The ratio of p21 and p53 positive cells was 1.0+/-0.1. CONCLUSION: We could note that the expression of p53 and p21 was the highest at an adjacent peri-infarct area. The degree of CBF reduction is more responsible for infarction than CBF itself.