关键词: 亚低温; 白细胞介素-6; 细胞间黏附分子-1; 脑缺血

Abstract: Objective To investigate the effect of mild hypothermia on the expression of ICAM-1 in the ischemia area and on the serum level of IL-6 concentration after middle cerebral artery occlusion (MCAO) in rats.Methods Thirty female Sprague-Dawley rats weighing 250-300 g were randomly assigned to the experiment group(n=15)and the control group(n=15). The unilateral MCAO models of rats were made by using suture embolism. After successfully making the MCAO models, the experiment group and the control group were treated by mild hypothermia and normothermia, respectively. For the experiment group, temperature was maintained at(33±1) after10 minutes, and for the contrl group, temperature was kept at(37±0.5). Twelve hours after cerebral ischemia, 4ml blood was drawn from left ventricles, then the brain was immediately and carefully extracted in each rat. Immunohistochemistry analysis was used to count the number of ICAM-1 positive microvessel in the ischemia area, and immunoradiometric assay(IRA) was used to analyze the serum level of IL-6. Results The number of ICAM-1 positive microvessel in the ischemia area of brain in the experiment group were significantly less than that in the control group (2.45±1.56)/HP vs (18.27±2.45)/HP, (P<0.01), but the serum IL-6 concentration and the neurological severity score in the control group are obviously higher than in the experiment group[(184±38)ng/L vs (124±41) ng/L, P<0.01, (2.13±0.35) vs (1.48±0.25), P<0.01, respectively].Conclusion Mild hypothermia can reduce the serum IL-6 concentration and the ICAM-1 expression in ischemia area after cerebral ischemia. We presume that decreasing the expression of IL-6 and ICAM-1 is one of the neuroprotective mechanism in treating ischemic stroke by using mild hypothermia.

Key words: Mild hypothermia; IL-6; ICAM-1; Cerebral ischemia