3,5-二羟苯甘氨酸诱导的大鼠脑缺血再灌注耐受模型

3,5-Dihydroxyphenylglycine-induced cerebral ischemia-reperfusion tolerance in rats

目的本研究尝试建立3,5-二羟苯甘氨酸(3,5-dihydroxyphenylglycine,DHPG)诱导的脑缺血耐受动物模型,为脑耐受机制研究提供新平台。方法选用健康雄性SD大鼠72只,随机分为正常对照组、假手术对照组、5个单纯全脑缺血15min再灌注组(0min,6h,12h,24h,48h)和5个DHPG预处理全脑缺血15min再灌注组(0min,6h,12h,24h,48h),按Pulsinelli-Brierley方法制作四血管全脑缺血模型,脑缺血前30min通过脑室内埋植套管注射DHPG或生理盐水3μl到右侧脑室;石蜡切片5μm,尼氏染色,海马CA1区健康神经元计数。结果随脑缺血再灌注时间延长,24h和48h神经元损伤最严重,健康神经元各为20.36±3.45、16.04±4.96,与对照组(55.96±3.17,53.28±2.94)相比有显著性差异(P<0.01);DHPG预处理组神经元损伤明显减轻,24h和48h的健康神经元各为44.34±4.42和40.34±4.42,与单纯全脑缺血再灌注组相比有显著性差异(P<0.01)。结论DHPG预处理对缺血神经元有保护作用。

Objective This study was designed to test the effect of 3,5-Dihydroxyphenylglycine （DHPG） on ischemia-reperfusion brain injury and to establish a new model of brain tolerance for future research. Methods Seventy-two SD rats （male, 200-350 g） were divided into 12 groups randomly： normal control group, sham-operated control group, 5 cerebral ischemia-reperfusion groups （reperfusion 0, 6, 12, 24 and 48 h after an ischemia of 15 min）, and 5 DHPG pre-treatment followed by cerebral ischemia-reperfusion groups （a DHPG pre-conditioning followed by 15 min ischemia and reperfusion for 0, 6, 12, 24 and 48 h）. In brief, whole brain ischemia-reperfusion was established using the Pulsinelli-Brierley method. Thirty minutes before induction of cerebral ischemia, 3 μl DHPG or vehicle （saline） were administered into the right lateral ventricle through inserted catheters. Thin sections （5 μm） of paraffin-embedded brain tissues were produced, subjected to Nissl＇s staining and then examined under light microscope. The number of healthy neurons in the hippocampal CA1 region was counted. Results Neuron injury was seriows in the 24 h and 48 h reperfusion groups. The numbers of healthy neurons in the 24 h and 48 h reperfusion groups were 20.36±3.45 and 16.04±4.96, respectively, significantly fewer than the control groups （55.96±3.17,53.28±2.94,P〈0.01）. The numbers of healthy neurons in the DHPG pre-treated 24 h and 48 h reperfusion groups were 44.34±4.42 and 40.70±4.26, respectively, significantly lower than those of the control groups （P〈0.01） but higher than those of the 24 h and 48 h reperfusion groups （P〈0.01）. Conclusion Our results indicate that a brief DHPG preconditioning induces tolerance of the brain to ischemia-reperfusion injury in the rat.