基于PI3K/Akt/mTOR信号通路探讨利多卡因改善大鼠蛛网膜下腔出血后迟发性脑血管痉挛的作用机制

To explore the mechanism of lidocaine in improving delayed cerebral vasospasm after subarachnoid hemorrhage in rats based on PI3K/Akt/mTOR signaling pathway

目的 探讨利多卡因对大鼠蛛网膜下腔出血后迟发性脑血管痉挛的改善作用及其作用机制。方法将30只SD雄性大鼠随机分为假手术组、模型组及利多卡因组,每组10只。根据改良Garcia神经功能评分评定大鼠神经功能;HE染色检测基底动脉横截面积评估血管痉挛;尼氏染色观察大鼠皮层和海马CA1区神经元形态改变;TUNEL染色观察基底动脉内皮细胞的凋亡情况;免疫荧光染色检测大鼠基底动脉Bcl-2、Bax及Cleaved caspase-3的表达情况;Westernblot检测基底动脉中Bcl-2、 Bax、 Cleavedcaspase-3、 PI3K、 p-Akt、 Akt及mTOR蛋白表达。结果 与模型组相比,利多卡因组大鼠神经功能评分明显提高(P<0.05);基底动脉管壁明显变薄,管径明显增大,痉挛缓解(P<0.05);皮层和海马CA1区神经元数量增加并且形态改善;基底动脉内皮细胞凋亡明显减轻(P<0.05);Bcl-2蛋白表达明显增加,Bax及Cleavedcaspase-3蛋白表达明显减少(P<0.05);基底动脉中PI3K、mTOR蛋白表达及p-Akt/Akt比值明显增加(P<0.05)。结论 利多卡因可通过激活PI3K/Akt/mTOR信号通路、轻基底动脉内皮细胞凋亡改善大鼠蛛网膜下腔出血后迟发性脑血管痉挛。

Objective To investigate the effect of lidocaine on delayed cerebral vasospasm after subarachnoid hemorrhage(SAH) in rats and its possible mechanism. Methods 30 male SD rats were randomly divided into sham group,model group and lidocaine group, with 10 rats in each group. The neurological function of rats was evaluated by the modified Garcia neurological function score after SAH. The cross sectional area of basilar artery was detected by HE staining.Morphological changes of neurons in the CA1 region of cortex and hippocampus were observed by Nissl staining. The apoptosis of basal artery endothelial cells was observed by TUNEL staining. The expression of bcl-2, Bax and Cleaved caspase-3 in rat basilar arteries were observed by immunofluorescence staining. The expression of Bcl-2, Bax, Cleaved caspase-3, PI3K, p-Akt, Akt and mTOR in basilar artery was detected by Western blot. Results Compared with model group, neurological function score of lidocaine group was significantly increased(P<0.05), basilar artery wall was significantly thinner and diameter was increased, and spasm was relieved(P<0.05). The number of neurons in cortical and hippocampal CA1 regions was increased and the morphology was improved. The apoptosis of basal artery endothelial cells was significantly reduced(P<0.05). The expression of Bcl-2 was increased significantly, the expression of Bax and Cleaved caspase-3 was decreased significantly(P<0.05). The expression of PI3K, mTOR and p-Akt/Akt ratio in basilar artery were increased significantly(P<0.05). Conclusion Lidocaine can improve delayed cerebral vasospasm after subarachnoid hemorrhage in rats by activating PI3K/Akt/mTOR signaling pathway and reduce basal artery endothelial cell apoptosis.