The temporal profiles of ICAM-1 expression and leukocytes infiltration after focal cerebral ischemia/reperfusion

Objective To study the temproal course of expression of ICAM-1 protein and the feature of neutrophils infiltration in rat brain after MCA occlusion/reperfusion. Methods The animal models of the MCA ischemia/reperfusion was established in Wistar rats. The expression of ICAM 1 was measured by immunohistochemistry and the neurtrophil infiltration was determined by the evaluation of MPO. Results (1)ICAM 1 immunoractivity was enhanced in microvessels in the ischemic lesion at 6h after reperfusion,reached the peak at 36～48h,and then decreased gradually,but at the 7th day,upregulation of ICAM 1 expression still existed. (2)Neurons also expressed ICAM 1 at the border of infarct. (3)MPO activity rose at 6h,reached the peak at 24～36h and then returned to near normal level at 6d. Conclusion (1)Up regulation of ICAM-1 in microvessel occured after ischemia/reperfusion,it also existed in neurons at the border of infarct. (2)The feature of neutrophils infiltration in ischemic region had the similar regularity to expression of ICAM-1.