电刺激小脑顶核对持续局灶性脑缺血时钙蛋白酶活性的影响

目的观察电刺激小脑顶核(FN)对持续局灶性脑缺血钙蛋白酶活性的影响,以阐明其神经保护作用机制。方法健康雄性Wistar大鼠,随机分为假手术组(PO)、FN刺激假手术组(PO-FN)、持续缺血组(PI)及持续缺血-FN刺激组(PI-FN),后两组又分为缺血1,3,6,12及24h组。建立大鼠电刺激FN及持续局灶性脑缺血模型,应用Western印迹半定量各组缺血核心区Mr=150000FBDP含量(表示钙蛋白酶活性),并应用尼氏体染色对缺血核心区神经元数量及形态进行分级评分。结果PO组及PO-FN组钙蛋白酶活性相似(P>0.05),处于低水平。PI组钙蛋白酶活性从缺血1h犤(3670±600)A/μg总蛋白犦开始即显著增高(t=6.338,P<0.001),以后随着缺血时间延长,钙蛋白酶活性不断增高,直至缺血24h犤(9180±360)A/μg总蛋白犦仍有持续增高趋势(缺血12,24h,t=14.673,16.632,P<0.001)。PI-FN组随着缺血时间的延长,钙蛋白酶活性从缺血1h犤(2510±460)A/μg总蛋白犦也开始增高,以后随着缺血时间延长,钙蛋白酶活性不断增高,但各时点组与其相应PI组相比,其增高程度明显减低,差别具有显著意义(缺血1,24h,t=1.875,2.134,P<0.05)。PO组及PO-FN组神经元形态及数量正常,评分均为0分。PI组从缺血1h(0.8±0.3)开始,神经元形态、数量即出现轻度改变,其评分增高(z=2.443,P<0.01),以

The effect of fastigial nucleus electrical stimulation on the activity of calpain during permanent focal cerebral ischemia

Aim To investigate the effect of fastigial nucleus(FN) electrical stimulation on the activity of calpain during permanent focal cerebral ischemia and to clarify it neuroprotective effect.Methods Heathy male Wistar rats were randomly divided into pretended operation(PO),FN stimulation pretended operation(PO-FN),persistant ischemia(PI) and persistant ischemia-FN stimulation(PI-FN) groups.The later two groups were divided into 1,3,6,12 and 24 h groups.FN electrical stimulation and middle cerebral artery occlusion(MCAo) model of rats were established.Western blotting was used for detecting the content of Mr=150 000 FBDP (representing calpain activity) and Nissl's staining, for scoring by neuronal number and size.Results Activities of calpain were similar in PO and PO-FN groups(P >0.05) and in a low level.Activity of calpain in Pi group increased signigicantly from ishcemia 1 h[(3 670± 600) A/μ g total protein,t=6.338,P< 0.001] and increased continuously with prolonging of ischemia duration until ischemia 24 h[(9 180± 360) A/μ g total protein, t=9.221,16.632, respectively at 3,24 h,P< 0.001].In PI-FN group,activity of calpain also increased from ischemia 1 h[(2 510± 460) A/μ g total protein] and increased continuously with prolonging of ischemia duration.But increasing level was obviously lower than that in PI group at corresponding phase(t=1.875,2.134, respectively at 1,24 h,P< 0.05).Neuronal appearance and number in PO and PO-FN groups were normal and scores were both 0.In PI group,neuronal appearance and number showed mild change and scores increased from ischemia 1 h( z=2.443, P< 0.01) .Scores increased continuously with prolonging of ischemia duration and reached climax until ischemia 24 h(4.0± 0.0)(z=1.875,2.018, respectively at 1,12 h,P< 0.05).In PI-FN group,scores in each groups within ischemia 1-12 h were singficicantly lower than those in PI groups at corresponding phases(z=1.875,2.018, respectively at 1,12 h,P< 0.05).But from ischemia 24 h(3.9± 0.2),the scores showed no significant differences compared with those in PI group at corresponding phases(P >0.05).Conclusion FN electrical stimulation can inhibit activity of calpain in focal cerebral ischemia and play neuroprotective effect.