丁苯酞对缺血性脑卒中大鼠记忆能力及海马5-HT1A受体和PKA信号通路活化的影响

目的:研究丁苯酞对缺血性脑卒中大鼠学习和记忆能力的影响和大鼠海马5-HT1A受体和PKA信号通路的调控作用。方法:将雄性SD大鼠随机分为假手术组、模型组和丁苯酞组(n=15)。丁苯酞组大鼠建立大脑中动脉闭塞模型,并按照每天60 mg/kg的剂量灌胃丁苯酞,假手术组和模型组灌胃等体积的玉米油,共给药2周。治疗完成后对各组大鼠进行神经功能缺损评估和Morris水迷宫测试(n=15)。通过磁共振成像(MRI)检测梗塞区域(n=15)。ELISA法检测海马组织PKA激酶活性(n=6)。使用钙检测试剂盒测定海马组织的细胞内Ca²⁺]浓度(n=6)。Western blot检测海马组织中5-羟色胺(1A)受体(5-HT1A)、谷氨酸N-甲基-D-天冬氨酸受体1(NMDA1)和α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体1(AMPA1)的表达(n=6)。结果:与模型组相比:丁苯酞组大鼠的逃避潜伏期显著降低,而穿越平台次数显著升高(P<0.05);大鼠的神经功能缺损评分和脑梗死体积较显著降低(P<0.05);大鼠的PKA激酶活性和细胞内Ca²⁺]浓度显著升高(P<0.05);丁苯酞组大鼠的5-HT1A蛋白相对表达量显著降低,而AMPA1和NMDA1的磷酸化水平显著升高(P<0.05)。结论:丁苯酞可改善缺血性脑卒中大鼠的学习和记忆能力,下调海马5-HT1A受体活性并激活PKA信号通路。

Effects of Butylphthalide on Memory Ability and Activation of 5-HT1A Receptor and PKA Signaling Pathway in Hippocampus of Rats with Ischemic Stroke

Objective:The aim of this study was to reveal the effect of butylphthalide on learning and memory ability of rats with ischemic stroke,and the regulation of butylphthalide on 5-HT1 A receptor and PKA signaling pathway in hippocampus of rats.Methods:Male Sprague-Dawley(SD)rats were randomly divided into a sham group,a model group and a butylphthalide group(n=15).A model of middle cerebral artery occlusion was established in rats in the butylphthalide group,and the rats were administrated orally with butylphthalide at a dose of 60 mg/kg per day for 2 weeks.The sham group and the model group were administered orally with equal volume of corn oil for 2 weeks.After the treatment,neurological deficit assessment and Morris water maze test were performed on each group of rats(n=15).The infarcted area was detected by magnetic resonance imaging(MRI)(n=15).ELISA was performed to determine PKA kinase activity in hippocampus(n=6).IntracellularCa²⁺]concentration in the hippocampus was measured using a calcium detection kit(n=6).Western blot was used to detect the expression of serotonin(1 A)receptor(5-HT1 A),N-methyl-D-aspartate receptor 1(NMDA1)andα-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor(AMPA1)in hippocampus(n=6).Results:Compared with the model group:the escape latency of rats in the butylphthalide group were significantly reduced,but the number of crossing platforms was greatly increased(P<0.05);the neurologic deficit score and cerebral infarction volume of rats were tremendously reduced(P<0.05);the PKA kinase activity and intracellularCa²⁺]concentration in rats increased dramatically(P<0.05);the relative expression of 5-HT1 A protein decreased markedly in rats in the phthalein group,while the phosphorylation level of AMPA1 and NMDA1 increased sharply(P<0.05).Conclusion:Butylphthalide can improve the learning and memory ability of rats with ischemic stroke,and down-regulate the activity of5-HT1 A receptor,and activate the PKA signaling pathway in hippocampus.