普仑司特对脑室周围白质软化新生大鼠的作用

Effect of pranlukast on neonatal rats with periventricular leukomalacia

目的探讨普仑司特(Pran)对脑室周围白质软化(PVL)新生大鼠的作用。方法将3日龄大鼠随机分为假手术(Sham)组、PVL组和Pran组。通过右侧颈总动脉结扎及术后缺氧建立PVL模型,Sham组大鼠仅游离右侧颈总动脉,不予结扎,也不进行缺氧处理。Pran组缺氧后经腹腔注射Pran(0.1 mg/kg),每12 h注射1次,连续注射3 d,Sham组和PVL组分别给予等量生理盐水腹腔注射。造模后14 d,通过苏木精-伊红染色法观察脑组织病理变化,免疫荧光染色法检测脑组织髓鞘碱性蛋白(MBP)表达(n=8),免疫印迹法测定环核苷酸磷酸二酯酶(CNPase)、MBP和G蛋白偶联受体17(GPR17)表达(n=8)。造模后21 d,应用Morris水迷宫实验评价各组大鼠的学习记忆能力(n=8)。结果 HE染色结果表明:PVL组与Sham组比较脑白质出现明显病理性改变,Pran组病理变化较PVL组明显改善。免疫荧光结果显示:PVL组MBP平均荧光强度低于Sham组,Pran组MBP平均荧光强度高于PVL组(P<0.05)。Western blot结果显示:PVL组MBP和CNPase蛋白相对表达均低于Sham组,GPR17蛋白相对表达高于Sham组(P<0.05);Pran组MBP和CNPase蛋白相对表达均高于PVL组,GPR17蛋白相对表达低于PVL组(P<0.05)。Morris水迷宫实验结果显示:PVL组与Sham组比较,逃避潜伏期延长,穿越平台次数减少;Pran组与PVL组比较,逃避潜伏期缩短,穿越平台次数增加(P<0.05)。结论 Pran可减轻PVL新生大鼠的脑损伤,促进髓鞘形成,改善远期学习记忆能力。其作用机制可能与下调GPR17的表达有关。

Objective To study the effect of pranlukast(Pran)on neonatal rats with periventricular leukomalacia(PVL).Methods The rats,aged 3 days,were randomly divided into a sham-operation group,a PVL group,and a Pran group.A rat model of PVL was prepared by right common carotid artery ligation and postoperative hypoxia.The rats in the sham-operation group were given isolation of the right common carotid artery without ligation or hypoxic treatment.The rats in the Pran group were given intraperitoneal injection of Pran(0.1 mg/kg)once every 12 hours,for 3 consecutive days,and those in the sham-operation group and the PVL group were given intraperitoneal injection of an equal volume of normal saline.On day 14 after modeling,hematoxylin-eosin(HE)staining was used to observe the pathological changes of brain tissue;immunofluorescent staining was used to measure the expression of myelin basic protein(MBP)in brain tissue(n=8);Western blot was used to measure the expression of cyclic nucleotide phosphodiesterase(CNPase),MBP,and G protein-coupled receptor 17(GPR17)(n=8).On day 21 after modeling,Morris water maze test was used to evaluate the learning and memory abilities of rats in each group(n=8).Results The results of HE staining showed that the PVL group had greater pathological changes of white matter than the sham-operation group,and compared with the PVL group,the Pran group had a significant improvement in such pathological changes.The results of immunofluorescence assay showed that the PVL group had a lower mean fluorescence intensity of MBP than the sham-operation group(P<0.05),and the Pran group had a higher mean fluorescence intensity of MBP than the PVL group(P<0.05).Western blot showed that compared with the sham-operation group,the PVL group had significantly lower relative expression of MBP and CNPase(P<0.05)and significantly higher relative expression of GPR17(P<0.05),and compared with the PVL group,the Pran group had significantly higher relative expression of MBP and CNPase(P<0.05)and significantly lower relative expression of GPR17(P<0.05).Morris water maze test showed that compared with the sham-operation group,the PVL group had a significant increase in escape latency and a significant reduction in the number of platform crossings,and compared with the PVL group,the Pran group had a significant reduction in escape latency and a significant increase in the number of platform crossings(P<0.05).Conclusions Pran can alleviate brain damage,promote myelination,and improve long-term learning and memory abilities in neonatal rats with PVL,possibly by reducing the expression of GPR17.