肺炎链球菌溶血素致幼鼠感染性脑损伤动物模型的建立

目的 探讨经颈内动脉注射肺炎链球菌溶血素(PLY)建立感染性脑损伤动物模型的方法和可行性.方法 采用颈内动脉注射PLY制作幼年大鼠感染性脑损伤动物模型.选取健康普通级1月龄SD大鼠160只,体质量100～120 g,雌雄不限,随机分为PLY组和对照组,其中PLY组(实验组)80只,颈内动脉注射PLY 0.2 mL(7 μg);对照组80只,颈内动脉注射等体积9g·L-1盐水.根据不同观察时间点(注射后6 h、12 h、24 h及48 h),将PLY组SD大鼠分为4个亚组,每个亚组中分别有10只注射伊文思蓝(EB),测定不同时间点脑组织EB水平;注射EB组经右颈外静脉近心端注入20 g·L-1 EB(2 mL·kg-1),推注时间1～2 min.各组处理后,待观察至相应时间点,将大鼠麻醉行心脏灌注后断头取脑,用于制作脑组织标本,以备观察.采用干湿质量法检测其脑组织含水量(BWC),甲酰胺法测定其脑组织EB水平,利用免疫组织化学法检测其脑组织神经元特异性烯醇化酶(NSE)、胶质纤维酸性蛋白(GFAP)的表达.结果 与对照组相比,HE染色光镜下观察,PLY组脑组织可见血管扩张、血管周围间隙增宽、炎细胞浸润、神经元空泡变性、星形胶质细胞体积增大肿胀、细胞核固缩等改变.各时间点PLY组BWC、EB水平、NSE及GFAP表达量均明显高于对照组,差异均有统计学意义(Pa＜0.01).结论 经幼鼠颈内动脉注射PLY可以成功建立幼鼠感染性脑损伤模型.

Establishment of Animal Models of Infectious Brain Injury Induced by Pneumolysin

Objective To explore the methods and feasibility via carotid artery injection of pneumolysin(PLY) create infectious brain injury animal model.Methods Models of acute infectious brain injury of rats were prepared by injected PLY via left internal carotid artery,160 1-month-old healthy Sprangne-Dawley(SD) rats,weight varied 100-120 g,were randomly divided into 2 groups.PLY group(n= 80),PLY 0.2 mL(7 μg) was injected via carotid for every rat;in control group(n=80),9 g·L-1 normal sodium(equal volume with the PLY) was injected each rat by the same methods as PLY group.PLY group according to the different observation time points after injection(6 h,12 h,24 h,48 h) was further divided into 4 sub-groups,each sub-group was 10 rats.The above mentioned sub-group,10 rats injected Evens blue(EB),at different time points for the determination of brain tissue EB.Within 1-2 minutes,injected EB group were given 20 g·L-1 EB via right external jugular vein with 2 mL·kg-1.Remains to be seen after treatment in each group to the corresponding point in time.At different time points,rats were decapitated to take brain tissue samples,then dry-wet weight method was used to detect the brain water content(BWC),formamide-method was used to detect EB content.The expressions of neuron specific enolase(NSE) and glial fibrillary acidic protein(GFAP)protein were investigated by immunohisto chemistry technology.Results In PLY groups,compared with control group,inflammatory cell infiltration,the clearance around vessels became broader,their cubage augmented than before and gliocyte cells became swelled.Nuclear appeared apoptosis among nerve cells and vacuolar degeneration occurred.The BWC,EB content and the expressions level of NSE and GFAP in PLY groups were all higher than those in control group,there were significant differences(Pa<0.01).Conclusion Injected PLY via carotid artery to rat that can be successfully established PLY-induced infectious brain injury model rats.