疏血通脉胶囊对脑缺血-再灌注大鼠p38 MAPK的影响

摘要

Objective To explore the neuroprotection of Shuxuetongmai capsule pretreatment, and the effect on the expression of p38 mitogen-activated protein kinase (p38MAPK) in rats with middle cerebral artery occlusion. Methods Ninety-six male SD rats were divided randomly into sham-operated group,ischemia/reperfusion group (I/R),ischemia preconditioning group (IP),and Shuxuetongmai group(n=24). Each group was further randomly divided into 4 subgroups by 3 h, 6 h, 24 h and 72 h after reperfusion, 6 rats in each subgroup. Sham-operated group was only performed artery separation . The middle cerebral artery occlusion (MCAO) model was set up in I/R rats by Longa method. The IP rats were performed for three minutes on the bilateral carotid artery ligation, and formed MCAO model 24 hours later. The rats in the Shuxuetongmai group were pretreated with Shuxuetongmai capsules for 14 days on gavage before the establishment of MCAO model. The neurological deficits were graded in rats by Zea Longa method. Western Blot was used to determine the protein expression of p38MAPK and P-p38MAPK. Tunel method was applied to detect the apoptosis of neurons and the relationship between expression of p38MAPK, P-p38MAPK and apoptosis of neuron. Results No neurological dysfunction appeared in the sham-operated group at each time points, but not for the other groups, which reached the peak at 24 h. Compared with the I/R group, IP group and Shuxuetongmai group presented the mild neurologic function deficiency at different time points in rats (P0.05). The obvious variation of the value of P-p38MAPK/p38MAPK wasn't detected in sham-operated group at different time points, while obviously presented in I/R group, and the ratios of P-p38MAPK/p38MAPK were increased gradually followed with reperfusion, approaching to the highest level at 24 h. Compared with the I/R group, the P-p38MAPK/p38MAPK declined from 3 h and to the lowest level at 24 h of reperfusion, in both IP and Shuxuetongmai groups(P0. 05). Conclusion Shuxuetongmai capsule pretreatment can induce brain ischemic tolerance, attenuate the apoptosis of neurons in cerebral ischemia reperfusion, and improve neurologic function. The mechanism may be related to the inhibition of p38MAPK phosphorylation.%目的：研究疏血通脉胶囊预处理对大脑中动脉闭塞再灌注大鼠脑保护作用及对脑内p38丝裂原激活蛋白激酶(p38MAPK)表达的影响。方法将96只雄性SD大鼠随机分为4组,每组24只,每组按照再灌注后3,6,24,72 h随机分为4个亚组,每个亚组6只。假手术组只分离动脉不插线。缺血-再灌注组建成大脑中动脉闭塞再灌注( MCAO)模型。预缺血组脑缺血预处理,24 h后建立MCAO模型；疏血通脉组先给予疏血通脉胶囊14 d,再制备MCAO模型。 Zea Longa法进行神经功能缺损评分,免疫印迹法检测p38MAPK、P-p38MAPK表达,Tunel 法检测神经元凋亡数量,观察p38MAPK、P-p38MAPK表达水平与神经元凋亡相关性。结果假手术组各时间点均未出现神经功能缺损,其余各组大鼠各时间点均出现不同程度神经功能缺损,并均于24 h达高峰。与缺血-再灌注组比较,预缺血组和疏血通脉组各时间点神经功能缺损情况较轻(P<0.05)。预缺血组与疏血通脉组各时间点神经功能缺损情况相当。假手术组不同时间点P-p38MAPK/p38MAPK比值未见明显变化；其他3组P-p38MAPK/p38MAPK比值增大,且随再灌注时间延长,该比值逐渐升高,24 h达到高峰。预缺血组和疏血通脉组从3 h起,P-p38MAPK/p38MAPK比值减小,并随再灌注时间延长逐渐下降,24 h最低,与缺血-再灌注组比较,均差异有统计学意义(P<0.05)。预缺血组与疏血通脉组不同时间点磷酸化水平相当。假手术组各时间点偶见极少量凋亡神经元,其他各组随再灌注时间延长,神经元凋亡数量逐渐增加,并于24 h达到高峰。预缺血组和疏血通脉组不同时间点神经元凋亡数量均较缺血-再灌注组少(P<0.05)。结论疏血通脉胶囊预处理可诱导大鼠脑缺血耐受,减少脑缺血-再灌注后神经元凋亡,改善神经功能,其机制可能与抑制p38MAPK磷酸化有关。