诱导型一氧化氮合酶和精氨酸酶1在癫痫共病抑郁大鼠各脑区中的表达比较

Comparison of expression of inducible nitric oxide synthase and arginase 1 in different brain regions of epileptic comorbid depression rats

目的对癫痫共病抑郁大鼠各脑区诱导型一氧化氮合酶(iNOS)和精氨酸酶1(Arg-1)表达及神经元凋亡情况进行分析。方法从实验室购得28只纯净级大鼠,随机分为四个组别,分别为对照组(n=7)、癫痫组(n=7)、慢性不可预见中等应激刺激的抑郁组(n=7)、氯化锂一匹罗卡品法构建的癫痫共病抑郁组(共病组)(n=7)。利用免疫组织化学检测四组大鼠的iNOS和Arg-1表达,以及利用TUNEL染色检测大鼠神经元凋亡情况。结果于造模完成之后的第4周末来进行行为学测试,抑郁组、共病组与另外两组相比表现为体质量、垂直运动、水平运动、糖水偏好率的大幅下降(P<0.05)。共病组与抑郁组相比,表现为水平运动和蔗糖偏好率的大幅下降(P<0.05);依据免疫组织化学染色结果可以看出,各组海马区、杏仁核、额前皮质三区的iNOS与Arg-1表达均呈阳性,且集中在细胞膜和细胞质当中,存在沉淀,颜色为棕褐色或棕黄色。就三区iNOS与Arg-1的表达来看,共病组与其他三组相比,前者表达大幅增多,后者表达大幅减少(P<0.05)。且就共病组来看,其海马区与另外两区相比有着显著更高的iNOS表达(P<0.05);依据TUNEL染色结果可以看出,TUNEL阳性细胞呈棕褐色的情况见于所有分组的三个脑区中。共病组与其他三组相比,三区的TUNEL阳性细胞数量大幅增加(P<0.05)。且就共病组来看,在TUNEL阳性细胞数量这一指标上,其海马区与另外两个脑区相比显著要高(P<0.05)。结论癫痫共病抑郁大鼠海马M1型小胶质细胞活化及凋亡神经元较额前皮质及杏仁核明显增多,其是iNOS和Arg-1诱导M1型小胶质细胞活化及凋亡神经元可能是癫痫共病抑郁发病的病因和机制之一。

Objective To analyze the expression of inducible nitric oxide synthase(iNOS)and arginase1(Arg-1)and neuronal apoptosis in brain regions of epileptic comorbidities depressive rats.Methods Twentyeight pure grade rats were randomly divided into four groups:control group(n=7),epilepsy group(n=7),chronic unforeseeable moderate stress depression group(n=7),and epilepsy comorbidity depression group(n=7)constructed by lithium chloride and pilocarpine method.Immunohistochemistry was used to detect the expression of iNOS and ARG-1,and TUNEL staining was used to detect the apoptosis of rat neurons.Results At the end of the fourth week after the modeling,the behavioral test showed that the depression group and the comorbidity group showed a significant decrease in body weight,vertical exercise,horizontal exercise and sugar water preference rate compared with the other two groups(P<0.05).Compared with the depression group,the comorbidity group showed a significant decrease in horizontal exercise and sucrose preference rate(P<0.05).According to the results of immunohistochemical staining,the expressions of iNOS and Arg-1 in hippocampus,amygdala and prefrontal cortex in each group were positive,and concentrated in the cell membrane and cytoplasm,with precipitation,and the color was brown or brown-yellow.Compared with the other three groups,the expression of iNOS and Arg-1 in the comorbidity group was significantly increased,and the expression of iNOS and Arg-1 in the comorbidity group was significantly decreased(P<0.05).In the comorbidity group,the expression of iNOS in the hippocampus was significantly higher than that in the other two regions(P<0.05).According to the results of TUNEL staining,the brown color of TUNEL positive cells was observed in all three brain regions.Compared with the other three groups,the number of TUNEL positive cells in the three zones was significantly increased in the comorbidity group(P<0.05).In the comorbidity group,the number of TUNEL-positive cells in the hippocampus was significantly higher than that in the other two brain regions(P<0.05).Conclusion M1 microglia activation and apoptotic neurons in hippocampus of epileptic comorbidities depression rats are significantly more than those in prefrontal cortex and amygdala.In fact,Ml microglia activation and apoptotic neurons induced by inducible nitric oxide synthase and arginase 1 May be one of the causes and mechanisms of epileptic comorbidities depression.