不同Hemin预处理条件对全脑缺血/再灌注大鼠海马CA1区迟发性神经元死亡的影响

目的 观察不同条件下氯化血红素(Hemin)预处理对全脑缺血/再灌注(I/R)大鼠海马CA1区迟发性神经元死亡(DND)的影响.方法 将102只雄性Wistar大鼠随机分成17组,应用四血管闭塞法复制I/R模型,予不同时间、不同剂量、不同途径、不同次数的Hemin预处理,观察(硫堇染色下)大鼠海马CA1区神经元组织学分级(HG)和神经元密度(ND),对DND进行评价.结果 所有Hemin预处理组大鼠海马CA1区HG和ND与Sham、I/R组比较,除I/R前48 h、20 mg/kg、1次灌胃预处理组外,结果存在差异(P＜0.05);所有Hemin预处理组中I/R前24 h、80 mg/kg、3次灌胃预处理组ND值最高,HG最低(P＜0.05);I/R前Hemin 50、80 mg/kg预处理组海马CA1区ND值高于20 mg/kg预处理组(P＜0.05),Hemin 50、80 mg/kg预处理组间ND值差异无统计学意义(P＞0.05);Hemin不同时间预处理ND值大小规律为I/R前24 h＞0.5 h＞48 h;Hemin灌胃给药效果好于腹腔注射(P＜0.05);I/R前Hemin3次预处理ND值高于单次预处理(P＜0.05).结论 HeminI/R前24 h、80 mg/kg、3次灌胃预处理下,或最有效减少I/R大鼠海马CA1区DND,发挥对脑组织的保护作用.

EFFECT OF DIFFERENT Hemin PRECONDITIONING ON DELAYED NEURONAL DEATH AT HIPPOCAMPUS CA1 REGION OF RAT AFTER GLOBAL CEREBRAL ISCHEMIA-REPERFUSION INJURY

Objective To study the effect of different Hemin preconditioning on delayed neuronal death(DND)at hippocampus CA1 region of rats after global cerebral ischemia-reperfusion injury.Methods 102 male Wistar rats were randomly divided into 17 groups and four vessels occluded to made global cerebral ischemia-reperfusion(I/R)model.Hemin preconditioning was carried out at different time,dose,route,and frequencies.Histological grade(HG)and neuronal density(ND)of hippocampal CA1 pyramidal neurons were observed after stained by thionine and then the DND was evaluated.Results Except the preconditioning group1,the results had significance difference(P<0.05).ND and HG of guoup12 was highest and lowest respectively in all Hemin preconditioning groups(P<0.05).ND at hippocampal CA1 region in I/R group which preconditioning with Hemin 50mg/kg,80 mg/kg was higher than treated by 20 mg/kg(P<0.05)before I/R,but there was no significant difference between the group of 50 mg/kg and 80 mg/kg(P>0.05).The ND results of treated by Hemin preconditioning in different times were 24 h>0.5 h>48 h before I/R.The effect of Hemin delivered by gastric perfusion was better than peritoneal injection(P<0.05).ND value after treated Hemin 3 times before I/R was higher than single time(P<0.05).Conclusion Hemin preconditioning with 24 h,80 mg/kg,3 times by gastric perfusion before I/R can decrease DND effectively at hippocampus CA1 region of rat after I/R and it may play an important role in protecting brain from injury.