Mild hypothermia effects on intercellular adhesion molecule-1 and serum interleukin-6 expression in brain tissues of a rat focal ischemia model

摘要

BACKGROUND: Previous studies have confirmed the neuroprotective effect of mild hypothermia on ischemic brain injury. OBJECTIVE: To investigate the effects of mild hypothermia on intercellular adhesion molecule-1 expression and serum interleukin-6 levels in ischemic brain tissues of focal brain ischemia rats, and to explore the neuroprotective effects of mild hypothermia on ischemic brain injury. DESIGN, TIME AND SETTING: A randomized, controlled, neurobiological experiment was performed at the Central Laboratory, First Affiliated Hospital, Xinxiang Medical College, China from February to July 2006. MATERIALS: Thirty healthy, adult, Sprague Dawley rats were used to establish middle cerebral artery occlusion models using the suture method. The immunohistochemistry (streptavidin-biotin-peroxidase complex method) kit was purchased from Boster, China. Interleukin-6 radioimmunoassay was supplied by Institute of Radioimmunity, Technology Development Center, General Hospital of Chinese PLA. METHODS: The rats were equally and randomly assigned into mild hypothermia and control groups, and middle cerebral artery occlusion models were established. The rectal temperature was maintained at (37 ± 0.5) ℃ in the control group. In the mild hypothermia group, the rectal temperature was maintained at (33 ± 1) ℃. MAIN OUTCOME MEASURES: At 12 hours after model establishment, the ischemic brain hemispheres were coronally sliced at the level of the optic chiasm. The number of intercellular adhesion molecule-1-positive vessels per high-power field was observed with an optical microscope. Serum interleukin-6 levels were measured by radioimmunoassay. RESULTS: Compared with the control group, intercellular adhesion molecule-1 and serum interleukin-6 expressions were significantly decreased in ischemic brain tissues of the mild hypothermia group (P < 0.01). CONCLUSION: Mild hypothermia exhibits a neuroprotective effect by reducing serum interleukin-6 and intercellular adhesion molecule-1 expression following cerebral ischemia.