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背景:反复高正加速度(+Gz)暴露可引起脑损伤,但其病理机制尚不清楚。目的:了解反复高正加速度(+Gz)暴露后大鼠脑组织中bcl-2,bax,p53和白细胞介素1β转化酶基因的表达变化,探讨细胞凋亡在反复高+Gz暴露所致脑损伤中的病理作用。设计:以SD大鼠为研究对象的随机对照实验研究。单位:一所医院的航空医学研究中心。材料:选用体质量为180～220g健康雄性SD大鼠26只,随机分成对照组和+Gz暴露组,其中对照组4只,+Gz暴露组22只。干预:将大鼠固定于动物离心机的转臂上,头朝向离心机轴心,+Gz暴露组条件为G值+14Gz,增长率1.5G/s,峰值持续时间45s,共作用3次,两次中间间歇0.5h。对照组大鼠亦在动物离心机上经历类似实验步骤,所承受的G值为+1Gz。分别于暴露后0.5,6.0,24.0和48.0h断头取脑。用半定量反转录聚合酶链反应方法检测对照组和+Gz暴露后0.5,6.0,24.0和48.0h大鼠脑组织中bcl-2,bax,p53和白细胞介素1β转化酶mRNA表达水平,并用原位末端脱氧核苷酸转移酶标记法检测脑组织中凋亡细胞。主要观察指标:各组大鼠+Gz暴露后大鼠脑组织中bcl-2,bax,p53和白细胞介素1β转化酶mRNA表达水平。结果:+Gz重复暴露后6h,大鼠脑组织bcl-2mRNA表达水平(0.32±0.08)明显低于对照组(0.69±0.15),bax,p53和ICEmRNA表达水平犤(.55±0.09),(
Background: Repeated high positive acceleration (+ Gz) exposure can cause brain damage, but its pathological mechanism is unclear. OBJECTIVE: To investigate the expression of bcl-2, bax, p53 and interleukin-1β converting enzyme gene in rat brain after repetitive high positive acceleration (+ Gz) exposure to investigate the effect of apoptosis on the brain after repeated high + Gz exposure Injury in the pathological role. DESIGN: Randomized controlled trial of SD rats. Unit: A hospital aviation medical research center. MATERIALS: Twenty-six healthy male Sprague-Dawley rats weighing 180-220 g were randomly divided into control group and + Gz exposure group, including 4 in control group and 22 in + Gz exposure group. Intervention: The rat was fixed on the revolving arm of animal centrifuge with the head facing the axis of the centrifuge. The condition of + Gz exposure group was G value + 14Gz, the growth rate was 1.5G / s, the peak duration was 45s, Intermittent two 0.5h. Control rats also underwent similar experimental procedures on animal centrifuges bearing a G value of + 1Gz. The rats were sacrificed at 0.5, 6.0, 24.0 and 48.0 h after exposure respectively. The expression of bcl-2, bax, p53 and interleukin 1 beta converting enzyme mRNA in brain tissues of control group and 0.5, 6.0, 24.0 and 48.0 h rats after exposure to + Gz were detected by semi-quantitative reverse transcription polymerase chain reaction Apoptotic cells in brain were detected by in situ terminal deoxynucleotidyl transferase labeling. MAIN OUTCOME MEASURES: The expression of bcl-2, bax, p53 and interleukin 1 beta converting enzyme mRNA in rat brain after Gz exposure were observed. Results: The expression of bcl-2mRNA in rat brain was significantly lower than that in control group (0.69 ± 0.15), bax, p53 and ICEmRNA expression at 6h after + Gz exposure