Baena R C, Busto R, Dietrich W D, Globus M Y, Ginsberg M D
Department of Neurology, University of Miami School of Medicine, FL 33101, USA.
Neurology. 1997 Mar;48(3):768-73. doi: 10.1212/wnl.48.3.768.
We investigated whether moderate, transient whole-body hyperthermia (approximately 39.6 degrees C), if imposed 1 day following a brief episode of forebrain ischemia, would affect the neuropathologic outcome. Forty-two Wistar rats were subjected to either a 5- or 7-minute period of bilateral common carotid artery occlusion plus hypotension (50 mm Hg), or to the equivalent sham procedure. Twenty-four hours later, rats of one subgroup were placed into a hyperthermic chamber containing high-intensity lamps designed to elevate rectal temperature to 39 to 40 degrees C for 3 hours. Normothermic subgroups received the same procedures, but the heating lamps were turned off. Eight days after brain ischemia or the sham procedure, brains were perfusion-fixed, and numbers of ischemic-appearing CA1 pyramidal neurons were counted. In rats with 7-minute forebrain ischemia, delayed hyperthermia increased mean numbers of ischemic neurons by 2.6- to 2.7-fold in all subsectors of area CA1 (p < 0.05, ANOVA). Delayed hyperthermia in 5-minute ischemic rats also tended to increase mean numbers of ischemic neurons (by 11-fold in lateral, 6-fold in middle, and 5-fold in medial CA1 subsectors), but these differences were not statistically significant. We conclude that moderate, transient hyperthermia, even if occurring 1 day after a 7-minute global ischemic insult, exacerbates the extent of ischemic neuronal injury.
我们研究了在前脑短暂缺血发作1天后施加适度的、短暂的全身热疗（约39.6摄氏度）是否会影响神经病理学结果。42只Wistar大鼠接受了5分钟或7分钟的双侧颈总动脉闭塞加低血压（50毫米汞柱），或同等的假手术。24小时后，一个亚组的大鼠被放入一个装有高强度灯的热疗室，这些灯旨在将直肠温度升高到39至40摄氏度并持续3小时。常温亚组接受相同的操作，但关闭加热灯。在脑缺血或假手术后8天，对大脑进行灌注固定，并对出现缺血的CA1锥体神经元数量进行计数。在经历7分钟前脑缺血的大鼠中，延迟热疗使CA1区所有子区域缺血神经元的平均数量增加了2.6至2.7倍（方差分析，p < 0.05）。5分钟缺血大鼠的延迟热疗也倾向于增加缺血神经元的平均数量（外侧CA1子区域增加11倍，中间增加6倍，内侧增加5倍），但这些差异无统计学意义。我们得出结论，适度的、短暂的热疗，即使在7分钟的全脑缺血损伤1天后发生，也会加剧缺血性神经元损伤的程度。
