Differences in p53 Protein Expression between Delayed and Completed Focal Cerebral Infarction in Rats

ABSTRACT

OBJECTIVE: We investigate and compare geometric patterns and degree of p53 protein expression in a peri-infarction area between two different types of cerebral infarction, delayed and completed focal cerebral infarctions. METHODS: For the delayed focal cerebral infarction group(Group 1 ; n=8), right middle cerebral artery(MCA) and bilateral common carotid artery(CCA) were ligated temporarily for thirty minutes, and their brains were obtained after 72 hours. For the completed focal cerebral infarction group(Group2 ; n=11), right MCA and CCA were occluded permanently, and contralateral CCA was occluded for thirty minutes, and their brains were obtained after 24 hours. RESULTS: The infarction volume was significantly larger in Group 2(267.2+/-29.6mm3) than that of Group 1(10.4+/-2.7mm3)(p<0.001). The width of p53 protein positive area was significantly longer in Group 1(107.8+/-60.5micro meter) than that in Group 2(75.0+/-7.1micro meter)(p<0.05). The density of p53 positive cell was more compact in group 2(48.2+/-1.7cells/HPF) than group 1(28.3+/-9.1cells/HPF)(p<0.001). CONCLUSION: It is suggested that the decreased p53 protein expression in the delayed infarction has certain roles other than apoptosis. The degree of p53 protein expression in the completed focal cerebral infarction seems to be closer to a critical level of gene expression that might determine cell death.