益生菌对调节脑梗死后大鼠运动功能的机制研究

Mechanism of probiotics regulating motor function in rats after cerebral infarction

目的探讨在脑梗死后康复期使用益生菌治疗促进大鼠运动功能恢复的机制。方法成年雄性SPF级7~8周龄Wistar大鼠,体重200~250 g,共35只。25只大鼠颅内注射内皮素制作脑缺血模型,模型制作后5只大鼠死亡,剩余20只大鼠按照随机数表法分为缺血组(ISC组)和缺血+益生菌组(ISC+PB组),每组10只。另外10只大鼠作为假手术组(SHAM组)。SHAM组大鼠仅使用生理盐水按照上述造模流程进行。各组均喂食普通大鼠饲料。ISC+PB组大鼠第7天开始使用益生菌VSL#3溶液进行灌胃,0.25 mL/(只·d)。采用原位末端转移酶标记(TdT-mediated dUTP nick-end labeling,TUNEL)凋亡试剂盒检测凋亡细胞。采用蛋白质免疫印迹法检测各组大鼠海马与梗死周边皮层脑源性神经营养因子(brain derived neurotrophic factor,BDNF)的蛋白水平变化。使用梯形平衡木测试大鼠的肢体运动功能。结果ISC组大鼠TUNEL阳性细胞数量较SHAM组显著增多(t=3.278,P=0.016),ISC+PB组大鼠的TUNEL阳性细胞数量低于ISC组(t=2.721,P=0.037)。ISC组大鼠海马与梗死周边BDNF蛋白表达水平高于SHAM组(t=2.012,P=0.032),ISC+PB组大鼠海马与梗死周边皮层BDNF水平较ISC组进一步提高(t=1.892,P=0.021)。梯形平衡木行走实验显示ISC组大鼠产生明显的运动功能损伤(t=3.425,P=0.041),而ISC+PB组错误率低于ISC组(t=4.131,P=0.024)。结论脑梗死后益生菌通过调控BDNF水平,抑制细胞凋亡,改善运动功能。

Objective To explore the mechanism of probiotics regulating the recovery of motor function in rats after cerebral infarction.Methods A total of 35 adult male SPF grade 7-8 weeks Wistar rats,weighing 200-250 g,were selected,25 of which were injected with endothelin to make cerebral ischemia models.Five rats died after modeling.The remaining 20 rats were randomly divided into two groups:ischemic(ISC)group and ischemic+probiotic(ISC+PB)group,with 10 rats in each group.Another 10 rats were used as sham operation(SHAM)group.The SHAM group was treated with normal saline according to the above modeling process.The rats in each group were fed with ordinary rat feeding.From the 7th day on,the rats were given probiotic VSl#3 solution by gavage,0.25 mL each day.TUNEL(TdT-mediated dUTP nick-end labeling)apoptosis kit was used to detect apoptotic cells.The levels of brain derived neurotrophic factor(BDNF)in hippocampus and the cortex around infarction were detected using Western Blot.Trapezoidal balance beam was used to test the limb motor function of rats.Results The number of TUNEL positive cells in ISC group was significantly higher than that in SHAM group(t=3.278,P=0.016),and that in ISC+PB group was lower than that in ISC group(t=2.721,P=0.037).The expression level of BDNF protein in hippocampus and periinfarct cortex in ISC group was significantly higher than that in SHAM group(t=2.012,P=0.032),and that in ISC+PB group was further higher than that in ISC group(t=1.892,P=0.021).Trapezoidal balance beam walking test showed that the rats in ISC group had obvious motor function injury(t=3.425,P=0.041).The error rate in ISC+PB group was lower than that in ISC group(t=4.131,P=0.024).Conclusion Probiotics after cerebral infarction can inhibit apoptosis and improve motor function by regulating the level of BDNF.