匹诺塞林对高血糖诱导的大鼠卒中后出血转化的作用

Role of pinocembrin in hyperglycemia-induced hemorrhagic transformation in rats after stroke

目的研究匹诺塞林(pinocembrin)对高血糖诱导的大鼠卒中后出血转化的作用。方法实验分为假手术组、大脑中动脉堵塞(MCAO)模型组、高糖+MCAO模型组、高糖+匹诺塞林+MCAO组。MCAO模型采用线栓法造模,缺血1.5 h;高糖+MCAO模型组于造模前30 min腹腔注射50%葡萄糖;高糖+匹诺塞林+MCAO组于再灌前5 min尾静脉注射匹诺塞林10 mg·kg-1。葡萄糖注射前、后30 min及MCAO术后1,2和3 h用血糖仪检测血糖。缺血24 h后,采用改良的大鼠神经功能缺损评分法进行神经学评分,TTC染色测定脑梗死体积,血红蛋白检测试剂盒检测脑组织中血红蛋白含量,伊文斯蓝渗漏实验观察对血脑屏障的影响,通过脑病理切片观察脑组织出血情况。全部实验结束后统计脑组织出血发生率和大鼠死亡率。结果MCAO模型组各时间点血糖水平与假手术组比较均无明显变化;高糖+MCAO模型组,提前30 min腹腔注射50%葡萄糖能使血糖水平从注射前4.0升至20.9 mmol·L-1,且各时间点血糖水平均显著高于MCAO模型组(P<0.01);匹诺塞林对高糖+MCAO模型大鼠血糖水平无影响。MCAO模型组和高糖+MCAO模型组的神经学评分(分别为9.4±1.5和10.0±0.6)无显著性差异;匹诺塞林使高糖+MCAO模型大鼠神经学评分降至7.4±1.1(P<0.01)。MCAO模型组脑梗体积为(23.3±11.3)%,高糖+MCAO模型组脑梗体积增加至(36.9±8.2)%(P<0.05),匹诺塞林使脑梗体积降至(26.9±5.8)%(P<0.05)。与MCAO模型组相比,高糖+MCAO模型组大鼠脑组织中血红蛋白含量和伊文斯蓝含量分别由(195.5±30.1)mg·L-1和(74.6±46.8)μg·g-1组织增加至(472.0±166.9)mg·L-1(P<0.01)和(132.9±49.6)μg·g-1组织(P<0.05);匹诺塞林可显著减轻高糖+MCAO模型大鼠出血损伤,使血红蛋白含量和伊文斯蓝含量降至(299.8±47.7)mg·L-1(P<0.01)和(70.4±39.2)μg·g-1组织(P<0.05)。MCAO模型组脑出血发生率和死亡率分别为18.2%和16.7%,高糖+MCAO模型组显著增加,分别为95.4%和57.3%;给予匹诺塞林后分别降至59.1%和18.9%。结论匹诺塞林能减轻高血糖诱导的出血转化,降低出血的发生率和死亡率,是一种具有潜力的抗出血转化药物。

OBJECTIVE To investigate the role of pinocembrin(Pino)in hyperglycemia-induced hemorrhagic transformation(HT)in rats after stroke.METHODS Rats were randomly divided into sham group,middle cerebral artery occlusion(MCAO)group,hyperglycemic(HG)+MCAO group and HG+Pino+MCAO group.The rats in HG+MCAO group received an intraperitoneal injection of 50%glucose(6 mL·kg-1).Pino(10 mg·kg-1)was administered 5 min before reperfusion.Before injection of glucose,30 min after injection and 1,2 and 3 h after MCAO,blood glucose was measured with the blood glucose meter.24 h after MCAO,modified Neurological Severity Scores(mNSS)were used to evaluate neurological function,TTC staining was used to measure infarct volumes.The hemoglobin content,Evans blue(EB)leakage and HE staining in brain tissue were used to evaluate the effect of Pino on hyperglycemia-induced HT.RESULTS No significant change in blood glucose was observed in the sham group or MCAO group.In HG+MCAO group,intraperitoneal injection of 50%glucose 30 min before surgery significantly increased the blood glucose level from 4.0 to 20.9 mmol·L-1.Pino had no effect on blood glucose.The neurological score was not significantly different between MCAO group and HG+MCAO group,which was 9.4±1.5 and 10.0±0.6,respectively.Pino reduced the neurological score to 7.4±1.1.The result of TTC staining showed that the infarct volume in MCAO group was(23.3±11.3)%and further increased to(36.9±8.2)%in HG+MCAO group.Administration of Pino could signifi⁃cantly reduce the infarct volume to(26.9±5.8)%.The results of hemoglobin content and EB leakage showed that hyperglycemia could aggravate brain damage,and increase the hemoglobin content and EB content from(195.5±30.1)mg·L-1 and(74.6±46.8)μg·g-1 tissue to(472.0±166.9)mg·L-1 and(132.9±49.6)μg·g-1 tissue,respectively.Compared with the HG+MCAO group,Pino significantly reduced hemoglobin content and EB content to(299.8±47.7)mg·L-1 and(70.4±39.2)μg·g-1 tissue,and improved bleeding injury.In addition,the incidence of HT and mortality of rats in the MCAO model group were 18.2%and 16.7%,but increased to 95.4%and 57.3%in HG+MCAO group,respectively.Administration of Pino reduced the incidence of HT and mortality of rats to 59.1%and 18.9%.CONCLU⁃SION Pino could improve hyperglycemia-induced HT,reduce the incidence of HT and mortality of rats,which may be a potential anti-HT drug.