电刺激小脑顶核与局灶性脑缺血再灌注时钙蛋白酶活性的关系(英文)

Relationship between fastigial nucleus electrical stimulation and calpain activity during focal cerebral ischemia and reperfusion

目的观察电刺激小脑顶核(FN)对局灶性脑缺血再灌注后钙蛋白酶活性的影响,以阐明电刺激FN在脑缺血再灌注中的神经保护作用机制。方法健康雄性Wistar大鼠,共120只,体质量250～300g。随机分入假手术组(PO)、FN电刺激假手术组(PO-FN)、缺血/再灌注组(I/R)及缺血/再灌注-FN刺激组(I/R-FN),后两组又分为再灌注1,3,6,12及24h组,每组10只。建立大鼠小脑FN电刺激及局灶性脑缺血再灌注模型,应用Western印迹半定量钙蛋白酶介导的150RU胞衬蛋白降解产物含量(可表示钙蛋白酶活性)及尼氏体染色进行神经元数量及形态分级评分,观察电刺激FN对缺血再灌注不同时间后,再灌注区钙蛋白酶活性及神经元损害程度的影响。结果再灌注1～3h,I/R组钙蛋白酶活性较I/R-FN组增高更显著犤分别由(6310±360),(4660±310)/μg总蛋白增高至(7060±290),(6240±310)/μg总蛋白,t=7.776,P=0.000及t=4.267,P=0.003〗。再灌注6～24h,I/R组钙蛋白酶活性不断增高,较FN-I/R组相应时点相比差异有极显著意义(各组P=0.000)。I/R组从再灌注1h(2.1±0.2)开始,神经元形态数量评分迅速增加,并随着再灌注时间延长,评分不断增高,至再灌注24h(4.0±0.0)达最高。I/R-FN组再灌注1～3h,神经元形态数量评分轻度增加,其后趋于稳定。至再灌注24h,神经元皱缩加重,神?

Aim To investigate the influence of fastigial nucleus electrical stimulation on the activity of calpain during focal cerebral ischemia and reperfusion and identify the neural protective mechanism of fastigial nucleus electrical stimulation.Methods 120 healthy male Wistar rats weighed 250-300 g were randomly divided into pseudo operation group(PO),FN electrical stimulation pseudo operation group(PO FN),ischemia/reperfusion group(I/R) and ischemia/reperfusion FN stimulation group(I/R FN).The later two groups were divided into 1,3,6,12,24 h groups respectively with 10 rats in each groups.FN electrical stimulation and MCAO and reperfusion model of rats were established.Using semi quantitative Western blotting for detecting the content of 150 RU FBDP (Calpain mediated fordrin breakdown pruduct)and Nissl's staining for scoring by neuronal number and size,we observed the changes of calpain activity and neuronal injury in reperfusion area after different time of focal cerebral ischemia and reperfusion in rats with or without FN electrical stimulation.Results Calpain activity increased obviously in I/R group compared with those in I/R-FN group [(6 310±360),(4 660±310)/μg total protein and (7 060±290),(6 240±310)/μg total protein,t=7.776,P=0.000 and t=4.267,P=0.003].After 6-24 h of reperfusion,calpain activity in I/R group increased gradually which had a statistical significance compared with that in I/R FN group(P=0.000 in each group).In I/R group,score of neuron number and size increased dramatically from 1 h of reperfusion(2.1±0.2), increased gradually and reach climax at 24 h(4.0±0). Score of neuron number and size in I/R FN group increased lightly at 1-3 h of reperfusion,then became stable.Shrinkage of neurons became more obvious at 24 h of reperfusion,score of neuron number and size increased again,but scores in each group were significantly lower than those in I/R group at each phase (z=2.356,P=0.018;z=2.008,P=0.045;z=2.887,P=0.004;z=2.685,P=0.007;z=2.835,P=0.005).Conclusion FN electrical stimulation can inhibit calpain activity during focal cerebral ischemia and reperfusion and protect the neuron from reperfusion injury.