BioScience Trends. 2008;2(6):241-244.
Influence of selective brain cooling on the expression of ICAM-1 mRNA and infiltration of PMNLs and monocytes/macrophages in rats suffering from global brain ischemia/reperfusion injury.
Cao JP, Xu JG, Li WY, Liu J
This study sought to evaluate the effects of selective brain cooling on the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA and infiltration of polymorphonuclear leukocytes (PMNLs) and monocytes/macrophages (MΦ) during global cerebral ischemia/ reperfusion (I/R). Global ischemia of the brain was produced by four-vessel occlusion for 30 min followed by reperfusion for 240 min. Thirty-five SD rats were randomly divided into five groups: group I had no ischemia and reperfusion; groups II, III, IV, and V were subjected to ischemia for 30 min at 37°C and reperfusion for 240 min at 37, 35, 32, and 28°C, respectively. Cerebral tissue samples were taken for pathological examination of the infiltration of PMNLs and MΦ and to detect ICAM-1 mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR). The expression of ICAM-1 mRNA and infiltration of PMNLs and MΦ increased more markedly in group II than in group I (p < 0.01), suggesting that hypothermia evidently inhibited ICAM-1 mRNA expression and PMNL and MΦ infiltration in the damaged cerebral tissue. In addition, significant differences were also found between group III and group II (p < 0.05) and among groups IV, V, and II (p < 0.01). These results suggest that I/R injury induces ICAM-1 mRNA expression and PMNL and MΦ infiltration in SD rats and that selective brain cooling, and especially moderate hypothermia (28-32°C), may provide better cerebral protection by markedly inhibiting the expression of ICAM-1 mRNA while decreasing the infiltration of PMNLs and MΦ in the brain.